Interior rearview mirror system

ABSTRACT

An interior rearview mirror system for a vehicle includes an interior rearview mirror assembly having a mirror casing, a reflective element and an application specific integrated compass chip. The application specific integrated compass chip includes at least two magnetoresponsive sensing elements established on a semiconductor substrate, and further includes associated circuitry commonly established with the magnetoresponsive sensing elements on the semiconductor substrate. Processing of an algorithm by a microprocessor of the interior rearview mirror system determines a directional heading of the vehicle responsive to a sensing of a magnetic field by the magnetoresponsive sensing elements and automatically compensates for a deviating magnetic field. An information display of the interior rearview mirror assembly displays the directional heading of the vehicle. The application specific integrated compass chip may have an area of less than approximately two square centimeters.

CROSS REFERENCE TO RELATED APPLICATIONS

The present application is a continuation of U.S. patent applicationSer. No. 12/766,160, filed Apr. 23, 2010, now U.S. Pat. No. 7,815,326,which is a continuation of U.S. patent application Ser. No. 12/575,726,filed Oct. 8, 2009, now U.S. Pat. No. 7,726,822, which is a continuationof U.S. patent application Ser. No. 12/370,043, filed Feb. 12, 2009, nowU.S. Pat. No. 7,600,878, which is a continuation of U.S. patentapplication Ser. No, 12/029,073, filed Feb. 11, 2008, now U.S. Pat. No.7,490,944, which is a continuation of U.S. patent application Ser. No.11/305,637, filed Dec. 16, 2005, now U.S. Pat. No. 7,329,013, whichclaims benefit of U.S. provisional application Ser. No. 60/636,931,filed Dec. 17, 2004, and U.S. patent application Ser. No. 11/305,637 isa continuation-in-part of U.S. patent application Ser. No. 10/456,599,filed Jun. 6, 2003, now U.S. Pat. No. 7,004,593, which claims thebenefit of U.S. provisional applications, Ser. No. 60/420,010, filedOct. 21, 2002; Ser. No. 60/398,240, filed Jul. 24, 2002; and Ser. No.60/386,373, filed Jun. 6, 2002, which are all hereby incorporated hereinby reference in their entireties; and the present application is also acontinuation-in-part of U.S. patent application Ser. No. 11/226,628,filed Sep. 14, 2005, which claims the benefit of U.S. provisionalapplications, Ser. No. 60/692,113, filed Jun. 20, 2005; Ser. No.60/677,990, filed May 5, 2005; Ser. No. 60/653,787, filed Feb. 17, 2005;Ser. No. 60/642,227, filed Jan. 7, 2005; Ser. No. 60/638,250, filed Dec.21, 2004; Ser. No. 60/624,091, filed Nov. 1, 2004, and Ser. No.60/609,642, filed Sep. 14, 2004.

FIELD OF THE INVENTION

The present invention relates generally to interior rearview mirrorassemblies for vehicles and, more particularly, to an interior rearviewmirror assembly which includes a compass system.

BACKGROUND OF THE INVENTION

Interior rearview mirror assemblies which include a directional orcompass display are known, such as the types disclosed in U.S. Pat. No.5,802,727, which is hereby incorporated herein by reference. Typically,such mirror assemblies include a compass sensor, such as amagnetoresistive sensor, a magnetocapacitive sensor, a magnetoinductivesensor, a Hall effect sensor, or a flux gate sensor or the like, whichis fixedly attached to the mirror mount that attaches the mirrorassembly to a mirror assembly mounting element, such as a conventionalmounting button mounted on an interior surface of the windshield of thevehicle. The mirror assemblies also include processing circuitry and acompass information display, typically included in the interior mirrorcasing (that includes the mirror reflector) which is pivotallyadjustable by the driver to suit his or her rearward field of view.

Predominantly, compass mirror assemblies in the market today involve thefixed placement of the compass sensor (and any locally associated sensorcircuitry), such as at the mirror mount where the mirror attaches to thewindshield or headliner of the vehicle. The compass system typicallyinvolves a cable/harness connection to the processing circuitry (whichis typically in the pivotable housing of the mirror assembly), which mayinclude the compass compensation circuitry and the like, which feeds orconnects to a display (such as a vacuum fluorescent (VF) display or thelike) that is typically included in the adjustable mirror casing (suchas behind the reflective element so as to display from behind andthrough the reflective element, or at an eyebrow or chin region of thebezel area of the mirror casing). The display then typically displays anoutput of the directional heading of the vehicle to the driver orpassenger of the vehicle, such as an eight point display, such as N, S,E, W, NE, NW, SE, SW, or the like.

It has been proposed in the art to mount the compass sensor within themovable housing of the rearview mirror assembly. Processes have alsobeen proposed to compensate for movement of the sensor during normal useof the mirror, such as when the mirror head or casing is adjusted by thedriver. Such proposed systems, such as described in U.S. Pat. Nos.6,140,933 and 6,023,229, which are hereby incorporated herein byreference, are often implemented with a specially adapted single ballmount or single pivot mirror assembly. Such compass mirror assembliescan be costly and often involve special tooling and complicatedadaptation of the mirror assembly itself and the casing of the mirrorassembly. Also, such compass systems as described in the patentsreferenced above are not readily adapted for use with double ball ordouble pivot mirror assemblies. Other compass systems and compasscompensation systems, such as the types described in U.S. Pat. Nos.4,581,827; 5,339,529; 5,455,716; 5,699,044; 5,737,226; and 5,808,197,and/or in PCT Publication No. WO 2004/076971 A2, published Sep. 10,2004; and/or in PCT Publication No. WO 2003/044540 A2, published May 30,2003; and/or in PCT Publication No. WO 2003/074969 A3, published Sep.12, 2003 (which are all hereby incorporated herein by reference), may beimplemented in interior rearview mirror assemblies, but may be costlyand difficult to implement within the movable mirror head of an interiorrearview mirror assembly with a single or double ball mountingarrangement.

Therefore, there is a need in the art for an interior rearview mirrorassembly having a compass system associated therewith that overcomes theshortcomings of the prior art.

SUMMARY OF THE INVENTION

The present invention is intended to provide an interior rearview mirrorsystem which includes a compass system having a display which indicatesthe general direction in which the vehicle is traveling.

According to an aspect of the present invention, a mirror and compasssystem includes an interior rearview mirror assembly having a reflectiveelement and a casing that are adjustable relative to a mountingstructure. A compass sensor having at least two magnetoresponsivesensing elements is positioned within the mirror casing and at aposition and orientation that reduces the effect of adjustment of themirror on the compass sensor output.

The compass sensor is preferably positioned at a generally centrallocation of the mirror and at or near the centerline of the mirror head.Preferably, the compass sensor is positioned at or near a lower regionof the mirror casing to position the sensor remotely from the roof ofthe vehicle and any wiring or lights or the like that may be positionedat the roof of the vehicle, in order to reduce the effect of such itemson the compass sensor performance.

Preferably, the compass sensor is oriented such that one of the sensingelements is generally along a longitudinal axis of the vehicle and theother sensing element is generally along a cross car axis of the vehiclewhen the mirror is oriented at a typical in-use position (such as at anangle of about 20 degrees rotation toward the driver side and at anangle of about 9 degrees tilt downward). Optionally, the system maydetermine when a prismatic mirror is flipped or toggled between thedaytime and nighttime orientations and may compensate or adjust theprocessing of the compass sensor output to compensate for the knownmovement (such as about 4½ degrees upward or downward) of the mirrorhead/reflective element and compass sensor.

Optionally, the compass sensor may be positioned in close proximity tothe mirror ball of the mounting arm (the ball that is received in thesocket at the mirror casing or reflective element or toggle portion ofthe mirror assembly) so as to reduce movement of the compass sensor whenthe mirror is adjusted, in order to reduce the effects of mirroradjustment on the compass sensor performance. Optionally, the compasssensor may be generally fixedly positioned relative to the mirror ballof the mounting arm so that the compass sensor is generally fixed and donot move during adjustments of the mirror head/reflective element whenthe driver grasps and moves the mirror head/reflective element to adjustto his or her preferred field of view rearward through the rear windowof the vehicle.

Optionally, the mirror and compass system may operate to enter a rapidcompensating and aggressive calibration mode in response to a detectionof an abrupt movement of the mirror head and compass sensor. The systemmay determine when such an abrupt movement is indicative of a mirroradjustment (such as an adjustment between the daytime and nighttimeorientations for a prismatic mirror or an adjustment of the mirror by aperson who has just entered the vehicle or started the vehicleignition), and then may enter the aggressive calibration mode inresponse to such a determination. The system thus may discern, such asalgorithmically via software and/or aided via a movement/mechanicaladjust detector/sensor element, between a change in sensor output thatis indicative of a mirror adjustment and a change in sensor output thatis indicative of a change in vehicle direction and may enter theaggressive calibration mode when the change in sensor output isindicative of a mirror adjustment. Such a mirror adjustment typicallyoccurs rapidly (such as in less than one second) and has a predictablerange and/or direction, so that the compass system can discern when achange in sensor output is indicative of a mirror adjustment versus adetection of a magnetic field anomaly or the like or versus a change indirectional heading of the vehicle.

According to another aspect of the present invention, an interiorrearview mirror system for a vehicle includes an interior rearviewmirror assembly, a casing having a reflective element, a compass sensorand a control. The casing is adjustable relative to a mounting structurethat mounts the interior rearview mirror assembly to an interior portionof the vehicle. The compass sensor has a first magnetoresponsive sensingelement and a second magnetoresponsive sensing element. The compasssensor is disposed within the mirror casing. The control receives afirst signal indicative of a magnetic field sensed by the firstmagnetoresponsive sensing element and receives a second signalindicative of a magnetic field sensed by the second magnetoresponsivesensing element. The control determines a directional heading of thevehicle based on the first and second signals. The control automaticallycompensates for a deviating magnetic field of the vehicle and generatesa signal indicative of the directional heading of the vehicle. Thecontrol determines that the casing is adjusted by an occupant of thevehicle in response to a change in the first and second signals beingindicative of an abrupt movement of the casing about the mountingstructure by an occupant of the vehicle (such as when the driver oroccupant of the vehicle adjusts the mirror reflective element to providea desired reflector rearward field of view). The control is operable toenter a rapid compensating mode to compensate for the mirror adjustmentin response to the control determining that the casing is adjusted by anoccupant of the vehicle.

According to another aspect of the present invention, an interiorrearview mirror system for a vehicle includes an interior rearviewmirror assembly, a casing having a reflective element, a compass sensorand a control. The casing is adjustable relative to a mounting structurethat mounts the interior rearview mirror assembly to an interior portionof the vehicle. The compass sensor has a first magnetoresponsive sensingelement and a second magnetoresponsive sensing element. The compasssensor is disposed within the mirror casing. The control receives afirst signal indicative of a magnetic field sensed by the firstmagnetoresponsive sensing element and a second signal indicative of amagnetic field sensed by the second magnetoresponsive sensing element.The control determines a directional heading of the vehicle based on thefirst and second signals and automatically compensates for a deviatingmagnetic field of the vehicle and generates a signal indicative of thedirectional heading of the vehicle. The control is operable to enter arapid compensating mode in response to an ignition cycle of the vehicle.The control automatically exits the rapid compensating mode and enters aless aggressive calibration mode that distinguishes the Earth's magneticfield from magnetic anomalies and non-abrupt changes in the vehiclemagnetic signature. The control automatically exits the rapidcompensating mode after a predetermined period of time has elapsed sincethe ignition cycle.

Therefore, the present invention provides a mirror and compass systemthat positions the compass sensor within the movable head portion of themirror assembly. The compass sensor is positioned in a manner thatreduces the effects of mirror adjustment on the sensor performance. Thesystem may adjust processing in response to known movements of themirror head to compensate for such known movements. The system may enteran aggressive calibration mode to calibrate the compass sensor when themirror has been adjusted by a user. The compass system may distinguishbetween the anomaly signature or pattern and the mirror adjustmentsignature or pattern and may enter the calibration mode when the mirroradjustment is detected.

These and other objects, advantages, purposes and features of thepresent invention will become apparent upon review of the followingspecification in conjunction with the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a forward facing elevation of an interior rearview mirrorassembly in accordance with the present invention, as facing forwardwith respect to a direction of travel of a vehicle;

FIG. 2 is a forward facing elevation of a interior rearview mirrorassembly of the present invention;

FIG. 3 is a sectional view of the interior rearview mirror assemblytaken along the line III-III in FIG. 2;

FIG. 4 is a top plan view of the interior rearview mirror assembly ofthe present invention;

FIG. 5 is a sectional view of the interior rearview mirror assembly ofFIG. 4;

FIG. 6 is a sectional view of another interior rearview mirror assemblyin accordance with the present invention; and

FIG. 7 is a sectional view of another interior rearview mirror assemblyand mounting assembly in accordance with the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring now to the drawings and the illustrative embodiments depictedtherein, a compassized prismatic interior rearview mirror assembly orsystem 10 includes a double pivot or double ball mounting arrangement 12for pivotally or adjustably mounting a casing 14, bezel portion 15 andprismatic reflective element 16 of mirror assembly 10 relative to aninterior portion of a vehicle, such as to an interior surface of awindshield 11 of a vehicle or the like (FIGS. 1-3). The mirror assembly10 includes a compass system 18, which includes a magnetoresponsivecompass sensor 20 and a display 22 for providing a display or indicationof the directional heading of the vehicle, such as at the reflectiveelement 16 of the mirror.

The mirror casing or housing 14 may comprise a polypropylene material orthe like and is adjustably mounted to a mirror mount (not shown)positioned at an interior portion of a vehicle, such as a mirrormounting button on a windshield of the vehicle or any other mountingmember at the windshield or at a headliner or overhead console of thevehicle or the like. The mirror housing may be adjustably mounted at thevehicle via connection to a single or double ball mounting arrangement,or via connection to any other mounting arrangement, without affectingthe scope of the present invention. The mirror housing 14 may then pivotor actuate around one or more ball and socket joints or connections tobe adjusted relative to the interior portion of the vehicle to a desiredorientation by the driver of the vehicle.

As shown in FIGS. 1 and 3, the double ball or double pivot mirrormounting arrangement 12 includes a mounting arm 12 a which is pivotallymounted at opposite ends to a mirror mount 12 b (mounted at thewindshield or headliner of the vehicle, such as at a mounting button atthe interior surface of the vehicle) and a mirror casing mount 12 c.Examples of double pivot or double ball mounting arrangements aredescribed in commonly assigned U.S. Pat. Nos. 4,646,210 and 6,331,066,which are hereby incorporated herein by reference. Preferably, themirror mounting components provide a breakaway type connection or mount,such as the types disclosed in U.S. Pat. Nos. 6,774,810; 6,642,851;6,483,438; 6,366,213; 6,326,900; 6,222,460; 6,172,613; 6,087,953;5,820,097; 5,377,949; and/or 5,330,149, which are hereby incorporatedherein by reference. Optionally, the mirror assembly may incorporate amounting arrangement of the types described in U.S. provisionalapplications, Ser. No. 60/692,113, filed Jun. 20, 2005; Ser. No.60/677,990, filed May 5, 2005; Ser. No. 60/653,787, filed Feb. 17, 2005;Ser. No. 60/642,227, filed Jan. 7, 2005; Ser. No. 60/638,250, filed Dec.21, 2004; Ser. No. 60/624,091, filed Nov. 1, 2004, and Ser. No.60/609,642, filed Sep. 14, 2004; and Ser. No. 60/729,430, filed Oct. 21,2005 by Hook for MOUNTING ASSEMBLY FOR VEHICLE INTERIOR MIRROR; and/orPCT Application No. PCT/US04/015424, filed May 18, 2004 by DonnellyCorp. et al. for MIRROR ASSEMBLY FOR VEHICLE, and published on Dec. 2,2004, as International Publication No. WO 2004/103772; and U.S. patentapplication Ser. No. 10/933,842, filed Sep. 3, 2004, now U.S. Pat. No.7,249,860; and/or Ser. No. 11/226,628, filed Sep. 14, 2005, which arehereby incorporated by reference herein. Optionally, and as shown inFIGS. 3-5, the mounting arrangement may comprise a single ball mountingarrangement, without affecting the scope of the present invention.

In the illustrated embodiment, the reflective element 16 comprises aprismatic reflective element. The prismatic interior rearview mirrorassembly may comprise any type of prismatic interior rearview mirrorassembly, such as the types described in U.S. Pat. Nos. 6,318,870;6,598,980; 5,327,288; 4,948,242; 4,826,289; 4,436,371; and 4,435,042;and PCT Application No. PCT/US2004/015424, filed May 18, 2004 byDonnelly Corporation et al. for MIRROR ASSEMBLY FOR VEHICLE, andpublished on Dec. 2, 2004, as International Publication No. WO2004/103772; and U.S. patent application Ser. No. 10/933,842, filed Sep.3, 2004 by Kulas et al. for INTERIOR REARVIEW MIRROR ASSEMBLY, now U.S.Pat. No. 7,249,860, which are hereby incorporated herein by reference.Optionally, the prismatic reflective element may comprise a conventionalprismatic reflective element or prism or may comprise a prismaticreflective element of the types described in U.S. patent applicationSer. No. 10/528,269, filed Mar. 17, 2005, now U.S. Pat. No. 7,274,501;Ser. No, 10/709,434, filed May 5, 2004 by Lynam for MIRROR REFLECTIVEELEMENT, now U.S. Pat. No. 7,420,756; Ser. No. 10/933,842, filed Sep. 3,2004 by Kulas et al. for INTERIOR REARVIEW MIRROR ASSEMBLY, now U.S.Pat. No. 7,249,860; Ser. No, 11/021,065, filed Dec. 23, 2004, now U.S.Pat. No. 7,255,451; and/or Ser. No. 10/993,302, filed Nov. 19, 2004 byLynam for MIRROR REFLECTIVE ELEMENT FOR A VEHICLE, now U.S. Pat. No.7,338,177; and/or PCT Application No. PCT/US03/29776, filed Sep. 19,2003 by Donnelly Corp. et al. for MIRROR REFLECTIVE ELEMENT ASSEMBLY;and/or PCT Application No. PCT/US2004/015424, filed May 18, 2004 byDonnelly Corporation et al. for MIRROR ASSEMBLY FOR VEHICLE, andpublished on Dec. 2, 2004, as International Publication No. WO2004/103772; and U.S. provisional application Ser. No. 60/525,952, filedNov. 26, 2003 by Lynam for MIRROR REFLECTIVE ELEMENT FOR A VEHICLE,which are all hereby incorporated herein by reference, without affectingthe scope of the present invention. A variety of mirror accessories andconstructions are known in the art, such as those disclosed in U.S. Pat.Nos. 5,555,136; 5,582,383; 5,680,263; 5,984,482; 6,227,675; 6,229,319;and 6,315,421 (the entire disclosures of which are hereby incorporatedby reference herein), that can benefit from the present invention.

The prismatic reflective element 16 may be formed from various materialssuch as plastic or glass, but preferably is glass, and preferably has aplanar front surface 16 a extending at an angle to a planar rear surface16 b (FIG. 3). Rear surface 16 b is preferably coated with a reflectivelayer of metal such as chromium, aluminum or alloys thereof as isconventionally known in the industry. The mirror casing 14 is pivotablerelative to mounting arm 12 a and mirror mount 12 b to pivot thereflective element 16 in order to reduce glare during nighttimeconditions. When the mirror casing is pivoted (such as via adjustment ormovement of a toggle tab or actuator 24) from a full reflectivitydaytime position to a reduced reflectivity nighttime position, thereflective surface 16 b is rotated or pivoted such that the uncoatedfront surface 16 a of reflective element 16 is aligned for viewing bythe vehicle driver instead of reflective surface 16 b. Preferably,reflective surface 16 b reflects at least about 60 percent to 95 percentof the light incident thereon, while the uncoated front surface 16 areflects about 4 percent of the light incident thereon, such that thereflective element significantly reduces glare from headlights or otherbright lights rearward of the vehicle to the driver's eyes when pivotedto the nighttime position. Although shown and described as having aprismatic reflective element, it is envisioned that many aspects of thepresent invention may be equally suitable and applicable toelectro-optic or electrochromic interior rearview mirror assemblieshaving electro-optic or electrochromic reflective elements, such asdescribed below.

As shown in FIGS. 4 and 5, when installed in the vehicle and adjustedfor viewing by a typical sized driver, the reflective element 16 isangled approximately 20 to 22 degrees toward the driver side (from alongitudinal axis 26 of the vehicle) and approximately 9 degreesdownward (from a generally horizontal plane 28) toward the floor of thevehicle. This is the nominal or typical position of the reflectiveelement when set to the daytime orientation. When the toggle 24 isflipped to set the reflective element to the nighttime orientation, themirror head (including the reflective element and casing and circuitboard and circuitry) is pivoted about 4½ degrees or thereabouts upwardor downward. Typically, prism flip angles range from about 3½ degrees toabout 5 degrees, and most typically are about 4¼ to about 4½ degrees.

The compass sensor 20 of compass system 18 functions to detect adirectional heading of the vehicle relative to the Earth's magneticfield, as is known in the art. The compass system and sensor may utilizeaspects of the compass systems described in U.S. patent application Ser.No. 10/352,691, filed Jan. 28, 2003 by Schierbeek et al. for VEHICLECOMPASS COMPENSATION, now U.S. Pat. No. 6,922,902; Ser. No. 10/933,842,filed Sep. 3, 2004 by Kulas et al. for INTERIOR REARVIEW MIRRORASSEMBLY, now U.S. Pat. No. 7,249,860; and/or Ser. No. 10/456,599, filedJun. 6, 2003 by Weller et al. for INTERIOR REARVIEW MIRROR SYSTEM WITHCOMPASS, now U.S. Pat. No. 7,004,593, and/or U.S. Pat. Nos. 4,546,551;5,699,044; 4,953,305; 5,576,687; 5,632,092; 5,677,851; 5,708,410;5,737,226; 5,802,727; 5,878,370; 6,087,953; 6,173,508; 6,222,460;6,513,252; and 6,642,851, and/or PCT Application No. PCT/US2004/015424,filed May 18, 2004 by Donnelly Corp. et al. for MIRROR ASSEMBLY FORVEHICLE, and published on Dec. 2, 2004, as International Publication No.WO 2004/103772, and/or European patent application, published Oct. 11,2000 under Publication No. EP 0 1043566, and/or Ser. No. 11/226,628,filed Sep. 14, 2005; U.S. provisional applications, Ser. No. 60/624,091,filed Nov. 1, 2004 by Karner et al. for MOUNTING ASSEMBLY FOR MIRROR ANDMETHOD OF MAKING SAME; and/or Ser. No. 60/630,061, filed Nov. 22, 2004by Lynam et al. for MIRROR ASSEMBLY WITH VIDEO DISPLAY, which are allhereby incorporated herein by reference. The compass circuitry mayinclude the compass sensor, such as a magneto-responsive sensor, such asa magneto-resistive sensor, such as the types disclosed in U.S. Pat.Nos. 5,255,442; 5,632,092; 5,802,727; 6,173,501; 6,427,349; and6,513,252 (which are hereby incorporated herein by reference), amagneto-capacitive sensor, a Hall-effect sensor, such as the typesdescribed in U.S. Pat. Nos. 6,278,271; 5,942,895 and 6,184,679 (whichare hereby incorporated herein by reference), a magneto-inductivesensor, such as described in U.S. Pat. No. 5,878,370 (which is herebyincorporated herein by reference), a magneto-impedance sensor, such asthe types described in PCT Publication No. WO 2004/076971 A2, publishedSep. 10, 2004 (which is hereby incorporated herein by reference), or aflux-gate sensor or the like, and/or may comprise a compass chip, suchas described in U.S. patent application Ser. No. 11/226,628, filed Sep.14, 2005; and U.S. provisional applications, Ser. No. 60/624,091, filedNov. 1, 2004 by Karner et al. for MOUNTING ASSEMBLY FOR MIRROR ANDMETHOD OF MAKING SAME; and/or Ser. No. 60/630,061, filed Nov. 22, 2004by Lynam et al. for MIRROR ASSEMBLY WITH VIDEO DISPLAY, which are herebyincorporated herein by reference.

The sensor circuitry and/or the circuitry in the mirror housing andassociated with the compass sensor may include processing circuitry. Forexample, and as shown in FIGS. 1 and 2, compass system 18 may include aprinted circuit board (PCB) 30, which may be mounted or positioned orbonded along the rear surface 16 b of the reflective element 16. Theprinted circuit board 30 may include all of the processing circuitry andthe compass sensor. The processing circuitry may include compensationmethods, such as those described in U.S. Pat. Nos. 4,546,551; 5,699,044;4,953,305; 5,255,442; 5,576,687; 5,632,092; 5,677,851; 5,708,410;5,737,226; 5,802,727; 5,878,370; 6,087,953; 6,173,508; 6,222,460;6,513,252; and 6,642,851, and U.S. patent application Ser. No.10/352,691, filed Jan. 28, 2003 by Schierbeek et al. for VEHICLE COMPASSCOMPENSATION, now U.S. Pat. No. 6,922,902; and Ser. No. 10/456,599,filed Jun. 6, 2003 by Weller et al. for INTERIOR REARVIEW MIRROR SYSTEMWITH COMPASS, now U.S. Pat. No. 7,004,593, and European patentapplication, published Oct. 11, 2000 under Publication No. EP 0 1043566,which are all hereby incorporated herein by reference. The compasssensor may be incorporated in or associated with a compass system and/ordisplay system for displaying a directional heading of the vehicle tothe driver, such as a compass system of the types described in U.S. Pat.Nos. 5,924,212; 4,862,594; 4,937,945; 5,131,154; 5,255,442; and/or5,632,092, and/or U.S. patent application Ser. No. 10/456,599, filedJun. 6, 2003 by Weller et al. for INTERIOR REARVIEW MIRROR SYSTEM WITHCOMPASS, now U.S. Pat. No. 7,004,593, and/or Ser. No. 11/284,543, filedNov. 22, 2005 by DeWind et al. for INTERIOR MIRROR ASSEMBLY WITHDISPLAY, now U.S. Pat. No. 7,370,983, and/or PCT Application No.PCT/US2004/015424, filed May 18, 2004 by Donnelly Corp. et al. forMIRROR ASSEMBLY FOR VEHICLE, and published on Dec. 2, 2004, asInternational Publication No. WO 2004/103772, and/or U.S. provisionalapplications, Ser. No. 60/630,061, filed Nov. 22, 2004 by Lynam et al.for MIRROR ASSEMBLY WITH VIDEO DISPLAY; and/or Ser. No. 60/667,048,filed Mar. 31, 2005, which are all hereby incorporated herein byreference.

When an interior rearview mirror that includes a compass system (such asa known compass system) is first installed in a vehicle at a vehicleassembly plant (such as when the mirror assembly (including the compasssensor and circuitry) is attached to a mounting button at a vehiclewindshield or other mounting portion at an interior portion of thevehicle) and first powered, known compass systems, which typically havethe compass sensor fixedly mounted at the mirror foot or base or mount,include an initial calibration mode intended to allow the vehicle to bedelivered from the assembly plant to an automobile dealership with thecompass appropriately calibrated. Taking, for example, such a knowninterior mirror compass system currently supplied by the assignee toautomakers, the compass system enters an aggressive calibration mode orrapid calibration/compensating mode (such as the Cal-1 mode as describedin U.S. Pat. No. 6,513,252, and U.S. patent application Ser. No.10/352,691, filed Jan. 28, 2003 by Schierbeek et al. for VEHICLE COMPASSCOMPENSATION, now U.S. Pat. No. 6,922,902, which are hereby incorporatedherein by reference) to calibrate the compass as the vehicle on theassembly line weaves and turns on the assembly conveyor line and as thevehicle is driven through the assembly plant and through the staging orstorage lot and onto a truck for shipping to a dealer. In so doing, theassignee's compass system determines three cardinal points (othercompetitive compass systems require detection of all four cardinal (N,W, S, E) points) and then deduces the true directional heading of thevehicle, compensating for the magnetic deviation inherent in thevehicle. After the vehicle is shipped to a dealer and purchased, thecompass system is calibrated and the correct heading is shown on thecompass display typically provided at the mirror reflector or at themirror bezel. After this initial Cal-1 or aggressive calibration hasbeen completed, calibration and/or compensation for stray magneticfields and other magnetic anomalies, such as typically encounteredexterior the vehicle during driving (and from the likes of metalbridges, subway lines, cellular telephone towers, large metal structuresand the like), are compensated for via other less aggressivecalibration/compensation modes. Thus, for example, and referring to U.S.Pat. No. 6,513,252 and U.S. patent application Ser. No. 10/352,691,filed Jan. 28, 2003 by Schierbeek et al. for VEHICLE COMPASSCOMPENSATION, now U.S. Pat. No. 6,922,902, and/or Ser. No. 10/456,599,filed Jun. 6, 2003 by Weller et al. for INTERIOR REARVIEW MIRROR SYSTEMWITH COMPASS, now U.S. Pat. No. 7,004,593, which are hereby incorporatedherein by reference, the compass system may initially operate in theaggressive Cal-1 calibration mode, and then may later function in a lessaggressive calibration/compensation mode, such as Cal-2 or Cal-3calibration modes.

Using the compass system of the present invention, as the vehicle istypically driven on highways (and with the compass system of the presentinvention in its normal operating mode or non-calibration mode), thecompass system is exposed to and may be affected by the various magneticanomalies, such as from bridges, cell towers, and/or the like referencedabove. Such magnetic anomalies, however, have a particular, and oftenpredictable, anomaly signature and/or pattern. The magnetic anomaliesmay impact the compass system performance and may lead to temporaryinaccurate compass readings and/or an erroneous compensation of thecompass system, and thus lead to display of erroneous/inaccurate compassdisplay headings.

The compass system of the present invention includes an algorithmexpressed in software processed by a microprocessor that includes amirror adjust detection routine. This mirror adjust detection routinetakes advantage of the fact that magnetic anomalies/stray magneticfields, which emanate from structures typically external to the vehicleas it passes by such structures and objects along a road or highway, aretypically temporary and relatively short lived because of the speed ofpassage of the vehicle. The mirror adjust detection routine furthertakes account of the fact that mirror adjustments by a driver of avehicle are relatively predictable events that occur abruptly and thatremain adjusted typically for the duration of that particular journey.Thus, the mirror adjust detection routine of the present inventionalgorithmically reduces or prevents or suppresses confusion of a mirroradjust event from other stray magnetic field/magnetic anomaly effectsthat are external to the vehicle. For example, the compass system of thepresent invention (via software operated by a microprocessor of thecontrol of the compass system) may distinguish and/or learn the patternand signature of such stray magnetic fields/magnetic anomalies and mayignore such and/or avoid entering particular calibration mode or modesor portions of modes when such anomalies are detected andrecognized/distinguished by the compass system.

Optionally, the compass sensing device or sensor 20 may comprise atwo-axis sensor (comprising two magneto-responsive sensing elementsdisposed at a fixed angle relative to each other, such as orthogonallyto each other, and disposed on a platform or circuit board or substrate32 so that they are positioned generally parallel to the floor plane ofthe vehicle so as to be sensitive to the horizontal component of theEarth's magnetic field), or the sensor may comprise a three-axis sensor(comprising two magneto-responsive sensing elements disposedorthogonally to each other and disposed in the mirror casing cavity, anda third magneto-responsive sensing element, sometimes referred to as az-axis sensing element, at a right angle (approximately ninety degrees)to the two sensing elements and disposed in the cavity, so that thethree-axis sensor is sensitive to the horizontal component and to thevertical component of the Earth's magnetic field), without affecting thescope of the present invention. The third axis sensing element is anoptional and not necessary addition to the sensor of the compass systemof the present invention. However, the z-axis sensing element may behelpful in detecting and distinguishing magnetic anomalies exterior tothe vehicle (as discussed above), but is not needed for the primarycompass direction determination and/or the detection of a tilt orrotation of the mirror. The compass sensor may be arranged at a desiredangle to provide enhanced sensing in the horizontal directions when themirror assembly is installed in the vehicle, as discussed below.

In the illustrated embodiment of FIGS. 4 and 5, the compass sensor 20includes a pair of sensing elements 20 a, 20 b positioned generallyorthogonal to one another. The pair of generally orthogonal sensingelements are preferably oriented relative to the vehicle such that oneof the sensing elements (20 a) is generally parallel to the floor of thevehicle and pointing generally forwardly in the direction of travel ofthe vehicle, while the other sensing element (20 b) is generallyorthogonal or perpendicular to the first sensing element and preferablyalso generally parallel to the floor of the vehicle. The compass sensorprovides an output signal to compass processing circuitry, which isoperable to process the output signal to determine the vehicle headingand to actuate or control or adjust an output of the display in responseto the output signal.

Optionally, and desirably, the compass sensor may be positioned at acompass sensor board or substrate 32 that may extend generallyhorizontally from the printed circuit board 30 at the rear of thereflective element 16. The compass sensor 20 may comprise a pair ofgenerally orthogonal sensing elements and thus may provide a two axissensing ability and function to provide direction sensing throughout therange of mirror adjustment with reduced or minimal impact on theaccuracy of the directional sensing during such adjustment. The impactmay be further reduced by various mounting arrangements orconfigurations and algorithms and the like, as discussed below.

As shown in FIGS. 2 and 4, the compass sensor is desirably positionedgenerally centrally from side to side within the mirror assembly, suchas along a centerline of the mirror assembly or along the longitudinalaxis 26, in order to reduce or minimize the affects or angular impact ofthe mirror adjustments on the compass sensor output. The compass sensoris also desirably positioned at or near a lower region of the circuitboard and mirror assembly, so as to be positioned further from the uppersheet metal or roof of the vehicle and further from the overhead wiringor lighting, or other devices or systems that may provide dynamicmagnetic disturbances, for enhanced performance of the compass sensor.

One of the sensing elements 20 a of the compass sensor 20 is preferablyoriented generally along or parallel to the longitudinal axis 26 of thevehicle and the other sensing element 20 b is preferably oriented alongor generally parallel to a lateral or cross-car axis 34 of the vehicle(in a side to side orientation and generally parallel to the vehiclefloor), with the sensing elements being generally normal or at a rightangle to one another. Optionally, and as shown in FIG. 4, the compasssensing elements 20 a, 20 b may be oriented relative to the mirrorreflective element so that the sensing element 20 a is generallyparallel to the longitudinal axis 26 of the vehicle, while the othersensing element 20 b is generally parallel to the lateral or cross-caraxis 34 of the vehicle when the reflective element is angled or orientedat the typical viewing position. The orthogonally oriented compasssensing elements 20 a, 20 b are thus positioned at their optimal anglefor the typical setting or position or orientation of the mirrorassembly during typical use of the mirror assembly in the vehicle.

For example, and as shown in FIGS. 4 and 5, the reflective element istypically rotatably angled horizontally and sidewardly toward the driverat an angle A, which is typically about 20 degrees (for a typicaldriver) relative to the cross car axis, and the reflective element istypically tiltably angled vertically and downwardly at an angle B, whichis typically about 9 degrees (for a typical driver) relative to avertical plane 36. Because the mirror casing and reflective element maybe pivoted to be angled generally toward the head of the driver of thevehicle, such as, for example, rotatably angled approximately 17-25degrees toward the driver side of the vehicle and tiltably angledapproximately 6 to 12 degrees downward, the compassized interiorrearview mirror assembly of the present invention thus may be adapted tomount the compass sensor on a physical mount or tilt/rotation offsetelement at the printed circuit board which compensates for orapproximates and effectively cancels the approximate angle of the mirrorcasing so as to orient the compass sensor generally in the desiredorientation, even when the mirror casing and reflective element areangled toward the driver of the vehicle (such as described in U.S.patent application Ser. No. 10/456,599, filed Jun. 6, 2003 by Weller etal. for INTERIOR REARVIEW MIRROR SYSTEM WITH COMPASS, now U.S. Pat. No.7,004,593, which is hereby incorporated herein by reference).

For example, a printed circuit board or equivalent may be positioned atand attached to the rear surface of the reflective element (the surfacewithin the casing of the mirror assembly and facing away from the driverof the vehicle when the mirror assembly is installed in the vehicle),such as via adhesive or an attachment or backing plate or the like. Thecircuit board may comprise a generally flat, rectangular element orsubstrate with conductive traces and circuitry disposed thereon. Whenthe mirror head and reflective element are arranged so that thereflective surface (the flat rear surface) of the reflective element isgenerally vertical, the circuit board is also generally verticallyoriented. Where a compass sensor chip (which may include a pair oforthogonally oriented sensing elements arranged in a common plane) isdisposed on and along the substrate or circuit board (PCB), the chipitself (and hence the sensing elements disposed therein) may be placedon the PCB in any orientation chosen by the PCB manufacturer. Thus, thecompass sensor chip may be oriented such that the principal axis of onesensor is generally horizontal and toward a side of the vehicle, whilethe principal axis of the other sensor may be generally verticallyoriented when the PCB is attached to a reflective element and thereflective element is generally vertically oriented. Thus, the actualplacement of the compass chip itself thus may largely or substantiallytake care of or account for the rotational orientation of the mirrorhead.

Because it is desired to provide sensing in the x-y directions (or in ahorizontal plane), the compass sensor is preferably disposed on acompass sensor mount or board that extends at an angle from the circuitboard and/or rear surface of the reflective element so that the compasssensor elements are generally horizontal when the mirror assembly isinstalled in the vehicle at its nominal (such as about 20 degreesideward and 9 degree downward) orientation. Preferably, the compasssensor mount is mounted to the circuit board such that the compasssensor mount is oriented at about a 9 degree downward angle from beingperpendicular or normal to the circuit board, such that the compasssensor mount or chip is substantially horizontal relative to the floorof the vehicle and thus the ground when the mirror head and reflectiveelement are oriented at the typical or nominal orientation with about a9 degree downward tilt toward the typical driver's head location.Likewise, the compass sensor is preferably mounted to the compass sensormount at an angle so that the principal axes of the compass sensingelements are at a desired respective angle relative to the reflectiveelement. For example, a first one of the sensing elements may be at anangle of about 20 degrees toward the driver side of the mirror assemblyrelative to the longitudinal axis of the vehicle, while a second sensingelement may be generally orthogonal to the first sensing element andalong the plane of the compass sensor mount. Thus, when the mirror headand reflective element are oriented at the typical or nominalorientation with about a 9 degree downward tilt and about a 20 degreesideward rotation toward the typical driver's head location, the sensingelements are oriented along a generally horizontal plane and areoriented such that the principal axis of the first sensing element is inthe direction of travel of the vehicle, while the principal axis of thesecond sensing element is normal to the first principal axis anddirected toward the side of the vehicle. The compass sensor mount may bemounted to the printed circuit board and/or the reflective element via agenerally wedge-shaped mounting element or offset element (or via othermounting means) or the compass sensor itself may be attached to ormounted to the printed circuit board at the desired angle, such as viaother mounting attachment means, to provide the desired orientation ofthe compass sensor relative to the reflective element. It is furtherenvisioned that the tilt/rotation offset element may be otherwise formed(or the compass sensor may be otherwise mounted to the circuit board) toprovide other offset angles depending on the particular application ofthe mirror assembly and the nominal orientation of the reflectiveelement that directs the reflective element generally toward thelocation of a typical driver to provide the typical driver with theappropriate or desired field of view rearward and through the rearwindow of the vehicle.

Thus, by using the tilt/rotation offset element of the presentinvention, typically a plastic molding that, for example, attaches tothe rear of the reflective element, an angled shelf or ledge is createdupon which rests the compass sensor itself and/or its printed circuitboard (PCB). Thus, when the interior rearview mirror assembly isinstalled in a vehicle, such as at the assembly plant (and adjusted at agenerally nominal position for viewing by a driver, such that thealgorithm can take over and generally or substantially calibrate thecompass system as the vehicle is moved through the vehicle assemblyplant), and/or is used by the average or typical driver, thetilt/rotation offset element compensates for the nominal 20 degreesideward rotation/9 degree downward tilt, such that themagneto-responsive sensing elements are oriented in the vehicle in whichthe mirror assembly is mounted with the principal axis of a first one ofthe magnetoresponsive sensing elements pointing directly forward throughthe windshield in the direction of travel of the vehicle, and with theprincipal axis of a second magnetoresponsive sensing element at 90degrees relative thereto and pointed sidewardly toward a side of thevehicle, and with both the first and second principalaxes/magnetoresponsive sensing elements lying in the same plane, andwith that plane being generally horizontal with the floor of the vehicleand thus with the road being traveled. Thus, the tilt/rotation offsetelement and/or the physical tilt and rotation offset means (that may betied to or separate from the offset element and/or sensor mount) of thepresent invention physically ensures that the compass sensor has atleast two magnetoresponsive sensing elements oriented generallyhorizontal to the ground (with one facing forward of the vehicle and onefacing orthogonally sideward). Thus, at the nominal (about 20 degreesideward/9 degree downward) mirror orientation or setting, the compasssensor is oriented in a known orientation relative to the Earth'shorizontal magnetic field. The mirror adjust detection algorithm orroutine of the present invention may reference against this as a base orreference orientation from which mirror/sensor adjustment is estimatedand/or accommodated/compensated against.

Optionally, in order to reduce the affect of mirror adjustment on thecompass sensor, the compass sensor may be mounted or positioned in closeproximity to the mirror ball (the ball (referred to at 13 a in FIG. 5)that is pivotally received at the mirror casing or toggle element of themirror assembly). Optionally, the compass sensor may be fixedlypositioned relative to the mirror ball (or may be mounted at the end ofthe mounting arm and mirror ball) so that there is reduced or little orno movement of the compass sensor during minor adjustments of thereflective element, such as when the reflective element is toggled orflipped between the daytime and nighttime orientations. For example, andas shown in FIG. 6, the compass sensor may be disposed on a circuitboard or platform 32′ that is attached to a portion of the mirror ball13 a′ of the mounting arm 13′, such as at a lower portion of the ball(to position the sensors remote from the roof of the vehicle). Anelectrical connector or wire or lead 38 may connect the compass sensorto the circuitry and display elements at the circuit board 30′ at thereflective element 16. As shown in FIG. 5, the mounting arm 13′ is partof a single ball mounting arrangement, but may be a mounting arm of adouble ball mounting arrangement, such as the type shown in FIGS. 1 and3, without affecting the scope of the present invention.

Optionally, and as described in U.S. patent application Ser. No.10/456,599, filed Jun. 6, 2003 by Weller et al. for INTERIOR REARVIEWMIRROR SYSTEM WITH COMPASS, now U.S. Pat. No. 7,004,593, which is herebyincorporated herein by reference, the printed circuit board 30 may bemounted at a physical mount at the reflective element to accommodate theapproximate angle of the mirror casing. The physical mount may be awedge shaped mounting element or bracket or any other means fororienting the compass sensor relative to the reflective element toaccommodate for the typical angle of tilt of the mirror head toward adriver of a vehicle. The typical angle or tilt of the mirror head orcasing may be calculated or otherwise determined or approximated and thephysical mount may then be formed to compensate or cancel the typicalangle of the mirror. The desired mounting orientation may vary dependingon the particular vehicle in which the compassized mirror assembly isbeing installed, since the mirror assembly may be mounted at differentheights along the windshield or at the headliner of different vehiclemodels. In lieu of a physical orientation as described above, softwarecompensation, as known in the art, can be used to negate or cancel outthe above effects.

Optionally, in applications where illumination sources or lights or anyother electrically conducting/powered electrical accessory or the likemay be sufficiently close to the compass sensor such that operation ofthe lights may impact the compass performance (due to the magnetic fieldgenerated by the current going through the lights), the lights may becontrolled or modulated via a pulse width modulation (PWM) control, sothat the lights are modulated between “on” and “off” settings by the PWMcontrol. The PWM control may be optimized to minimize emissions and tomaintain vehicle lighting requirements. The compass algorithm or controlor microprocessor may monitor the PWM control and may enter a differentoperation mode when the lights are being PWM controlled. For example,the compass control may optimize the hardware for through put and maysynchronize the light's PWM “off” time with the data collection by thecompass sensors, in order to reduce or minimize the impact of the fieldgenerated by the current passing through the wires when the lights areon or energized. Preferably, the lighting requirements may be maintainedwhile allowing sufficient time for the compass system signals to settleafter the PWM signal for the light is shut down or off. The preferred ordesirable settings may be selected based on a compromise between theemission of the illumination source or sources and the ability tosuccessfully read the compass sensor signals or output at the desiredaccuracy.

As described above, adjustment of the mirror housing (that includes themirror reflective element) about its pivot connection to its support(typically a double-ball support arm as described above, although asingle-ball support arm can also be used, without affecting the scope ofthe present invention) to the windshield (or to a header region at thejoint of the windshield and the roof of the interior cabin of thevehicle) can cause the compass direction sensing sensor attached to therear of the mirror reflective element to also move. Thus, the compasscontrol circuitry may detect a change in sensed compass directionalsignal (for example, about 3 degrees to about 8 degrees or thereabouts)when the mirror is adjusted by a driver of the vehicle. Should thevehicle be heading in a direction that is close to half-way between oneoctant or another in an eight-octant resolving compass display system,this adjustment by the driver of the mirror housing to set the rearwardfield of view of the mirror reflective element to suit that driver'sneeds/preference (typically occurring when the driver starts thejourney) may cause the heading displayed to the driver to change from,for example, NW to N, because the adjustment by the driver of the mirrorhousing has changed the orientation/alignment of the magnetic fielddetecting elements of the compass sensor (for example, amagnetoresistive sensor or Hall effect sensor) relative to the Earth'smagnetic field. Modern automatic automotive compass control systems,such as those described in U.S. Pat. Nos. 4,546,551; 5,699,044;4,953,305; 5,576,687; 5,632,092; 5,677,851; 5,708,410; 5,737,226;5,802,727; 5,878,370; 6,087,953; 6,173,508; 6,222,460; and 6,513,252,U.S. patent application Ser. No. 10/352,691, filed Jan. 28, 2003 bySchierbeek et al. for VEHICLE COMPASS COMPENSATION, now U.S. Pat. No.6,922,902, and European patent application, published Oct. 11, 2000under Publication No. EP 0 1043566, which are all hereby incorporatedherein by reference, comprise processing circuitry that includescompensation methods that correct for such changes in sensed compassheading. Thus, and as indicated in U.S. Pat. No. 6,642,851, which ishereby incorporated herein by reference, such known compensation methodscan be used to recalibrate the compass mirror system of the presentinvention after adjustment of the mirror housing by the driver.

Techniques and methods for compensating for such adjustments, such assuggested in U.S. Pat. No. 6,418,376 (the entire disclosure of which ishereby incorporated herein by reference), may be used in conjunctionwith the present invention. Such methods use a position sensor (such asa tilt sensor) that determines displacement of the mirror housing withrespect to a generally horizontal plane. For example, the compass systemof the present invention may incorporate a tilt sensor or positionsensor or rotation sensor or sensing means or element (such as a tiltsensor, a clinometer or a protractor or the like) that is operable todetect the position or orientation or movement of the mirror and compasssensors relative to a generally horizontal plane and/or a generallyvertical plane. For example, the compass system may incorporate anelectronic tilt sensor or clinometer, such as the types commerciallyavailable from various sources, such as, for example, from Schaevitz®Sensors of Hampton, Va., such as an AccuStar® electronic clinometer orthe like, and which may have a have a resolution of about 0.001 degreesand a range of about 60 degrees or thereabouts, and that may provide aanalog, ratiometric, digital pulse width, or serial output. Optionally,for example, the compass system may incorporate an electrolytic tiltsensor, which includes electrically conductive fluid that remainssubstantially level as the sensor body is tilted, whereby theconductivity between a pair of electrodes within the sensor body isproportional to the length or amount of the electrode immersed in theconductive fluid, such that the degree of tilt may be determined. Suchelectrolytic tilt sensors are commercially available from varioussources and may provide accurate pitch and roll measurements andenhanced repeatability, stability, and accuracy when operating at lowfrequencies. For example, a dual-axis, or 5-pin, sensor may be packagedin a cylindrical vial that stands between about ½ inch to about 1 inchhigh, and that provides an operating range of tilt from about ±10degrees to about ±75 degrees. Optionally, the compass system mayincorporate an AMR (anisotropic magnetoresistive) magnetic field sensoror the like, which may provide a tilt detection/determination. Othertilt sensors, clinometers, protractors, electrolytic sensors and/or thelike may be implemented with the compass system, without affecting thescope of the present invention.

Optionally, the mirror ball and/or mirror socket may include atransducer/sensor that may determine the orientation of the mirror ballrelative to the mirror socket. As the ball rotates in the socket (suchas due to adjustment of the mirror head/reflective element by thedriver), the orientation of the ball relative to the socket is detectedand transmitted or communicated to the control/microprocessor of thecompass system. The compass system may then determine the angularadjustment and may adjust the sensor processing and/or compensate forthe angular change in response to the detected angular change in theposition/orientation of the mirror head relative to the ball of themounting arm.

The control or circuitry or microprocessor may adjust the degree ofcompensation of the compass sensor output in response to the output oroutputs of the position sensor/sensors. Optionally, other techniques,such as the techniques and methods described in U.S. Pat. Nos. 6,140,933and 6,023,229, which are hereby incorporated herein by reference, mayalso or otherwise be implemented.

Optionally, a magnetic field emitter or radiator or generator may beplaced in a known fixed location within the vehicle interior cabin (forexample, the magnetic field emitter may be placed as part of the mirrorfoot or mount or base that fixedly attaches to the mirror mountingbutton or may be otherwise fixedly positioned relative to the vehicle).The magnetic field emitter may optionally be operated to emit a magneticfield in a pulsed and/or coded magnetic field signature. The magneticfield signature/signal emitted by the fixed magnetic field, emitter orsource will be picked up by the x-y orthogonally orientedmagnetoresponsive sensing elements of the compass sensor (that arepositioned within the movable mirror head and that move with the mirrorhead as it is pivoted about its single or double ball joint support),and thus that move relative to the fixed magnetic field emitter. Becausethe physical location of the fixed magnetic field emitter is known, theemitter can function as a homing beacon for the movable head/sensingelements, and thus a triangulation algorithm or the like can be used todetermine the particular orientation of the sensing elements and anydeviation from a known orientation. The compass sensor thus may detectthe emitted magnetic field (such as when the emitter is pulsed) and thecontrol or circuitry or microprocessor may process the compass sensoroutput (such as the output signal that corresponds to when the emitteris pulsed) to discern or distinguish the pulsed magnetic field orsignature magnetic field as emitted by the fixed magnetic field emitterto determine the orientation of the mirror head and compass sensorrelative to the fixed magnetic field emitter, and thus to determine thedegree of adjustment of the mirror head or reflective element relativeto the mounting base or known initial orientation or the like. Thecontrol may then adjust or alter the directional heading signal and/orthe display output in response to the detection of a change inorientation or position of the mirror head relative to the fixedreference point.

Optionally, an algorithmic technique may be implemented whereby, when anabrupt change in detected heading is detected that is characteristic ofan adjustment of the mirror housing by the driver of the vehicle, theautomatic compass circuitry changes its calibration status from itsongoing state (that compensates for such heading changes over aprolonged period, and one that typically may span an ignition cycle ofthe vehicle or several vehicle ignition cycles) to a more aggressive,faster calibration stage (such as a Cal-1 or Cal-2 calibration mode asdescribed in U.S. Pat. No. 6,513,252 and U.S. patent application Ser.No. 10/352,691, filed Jan. 28, 2003 by Schierbeek et al. for VEHICLECOMPASS COMPENSATION, now U.S. Pat. No. 6,922,902, which are herebyincorporated herein by reference) that more rapidly, and preferablywithin that same ignition cycle, recalibrates the compass system and socompensates for the driver's adjustment of the mirror housing/casing andfor the concomitant movement of the compass sensor housed therein.

Thus, for example, when a change in compass heading is detected that isindicative of and characteristic of an adjustment of the mirror housingby the driver, such as to adjust the mirror to provide a desiredrearward field of view (such adjustment causes an abnormal change of thecompass output that is different, such as by magnitude and/or rate ofchange, than what would occur during normal driving), then thecalibration changes to a faster or rapid or more aggressivecompensation/calibration algorithm/method. Such mirror adjustments aretypically within the range of plus or minus about 2 to 4 degrees upwardor downward from the nominal downward angle (of about 9 degreesdownward) of the mirror head/reflective element, and plus or minus about3 to 5 degrees to either side from the nominal sideward angle (of about20 degrees toward the driver side) of the mirror head/reflectiveelement. Such mirror adjustments, which typically occur rapidly, such aswithin less than about one to two seconds or thereabouts, create theirown known and predictable signature or pattern and thus may be detectedand discerned by the compass system. Thus, and referring to U.S. Pat.No. 6,513,252 and U.S. patent application Ser. No. 10/352,691, filedJan. 28, 2003 by Schierbeek et al. for VEHICLE COMPASS COMPENSATION, nowU.S. Pat. No. 6,922,902, and/or Ser. No. 10/456,599, filed Jun. 6, 2003by Weller et al. for INTERIOR REARVIEW MIRROR SYSTEM WITH COMPASS, nowU.S. Pat. No. 7,004,593, which are hereby incorporated herein byreference, upon detection of a change in compass heading that isindicative of and characteristic of an adjustment of the mirror housingby the driver, the calibration of the compass system would reinitiateback from Cal-3 (or Cal-2) to the beginning of Cal-1. Note that amechanical element such as a mechanical movement detector can be used todetect adjustment by the driver of the mirror housing, and therecalibration can be initiated in response to a signal output of such amechanical element.

Desirably, if a mirror adjustment is detected that is beyond the normalrange or zone of adjustment of the mirror (such as may occur if thepassenger angles the mirror toward the passenger side to borrow themirror or the mirror is otherwise rotated away from the driver, or suchas may occur if the mirror is inadvertently hit or moved to a severelyadjusted condition such that no reasonable driver would reasonably viewrearwardly through the rear window with the mirror so adjusted), thecompass system may detect and discern such egregious or non-normalmovement/adjustment and may suspend the calibration activities becausesuch movement/adjustment is an abnormal and typically temporarycondition. The compass system may return to its normal and/orcalibration mode of operation when the mirror head/reflective element isreturned to within the normal range of angularadjustment/position/orientation, such as within a predetermined degreeupward/downward and sideward of the nominal position/orientation.

For example, the compass compensation or calibration process may providefor initialization of a rapid or aggressive calibration stage inresponse to movement of the mirror housing by the driver grasping andmoving the mirror head/reflective element to adjust to his or herpreferred field of view rearward through the rear window of the vehicle.The compass circuitry may be operable to detect and discern ordistinguish a change in the sensed heading which is characteristic of anadjustment of the mirror housing by a driver of the vehicle. The compasscircuitry then may respond by reinitializing the compass calibration tothe rapid or aggressive calibration stage or mode. The compass circuitrythen may compensate for the movement of the compass sensor caused by theadjustment of the mirror housing via a microprocessor-based algorithmsoftware. After completion of the rapid calibration stage, such as afterthe compass sensor is re-calibrated or after a predetermined amount oftime following the onset of the rapid or aggressive calibration stage,the compass circuitry may return to its normal operation.

Optionally, the compass circuitry/software can set or return to thebeginning of the aggressive calibration stage (such as to the beginningof Cal-1 as described above) each time the mirror compass circuitry isinitially powered, such as by a fresh ignition cycle of the vehicle.Thus, for example, should a driver or occupant of the vehicle adjust theinterior rearview mirror orientation during the immediately previousignition cycle, and thus potentially disturb the established propercompass calibration, then an aggressive and rapid recalibration mayautomatically occur at the start of the following or next ignition cycle(and thus any potential calibration misalignment may only be temporarilyexperienced by the driver). Optionally, such an aggressive recalibrationmay occur in response to actuation of a key fob or remote keyless entrydevice or remote starter device or the like.

Optionally, the degree of aggression of the rapid calibration stage maybe effected by the time elapsed between the ignition activation (oractuation of the key fob or remote keyless entry device or the like) andthe perceived or detected adjustment of the mirror. For example, if thecircuitry detects an abrupt adjustment of the sensor orientation withina threshold time after the ignition is activated, then the control maydetermine that the change in orientation is due to a mirror adjustment(such as may occur when the driver first enters the vehicle and beforeor soon after shifting into drive or reverse) and thus may enter therapid and aggressive calibration mode. Optionally, the microprocessor orcontrol may include a first start protocol that causes the compasssystem to enter the aggressive calibration mode in response to the firstever startup of the vehicle ignition, such as typically occurs at thevehicle assembly plant.

Optionally, the compass system may acquire directional heading data atthe activation of the ignition (or activation of a key fob or the like)and, if an adjustment of the mirror head is detected soon after suchactivation, the compass system may acquire heading data with the sensorsat the new orientation. Because the initial heading data sampled afterthe ignition cycle may be correct data or may be indicative of thevehicle heading, the compass system may compensate or adjust the newdata to account for the change in orientation of the compass sensor fromthe initial and adjusted position. The compass system thus mayalgorithmically adjust the compass heading or sensor processing toaccount for the perceived movement or adjustment of the mirror headwithout entering the aggressive calibration mode.

Optionally, the degree of aggression or entry into the rapid aggressivecalibration mode may be affected by the speed of the vehicle when thechange in orientation of the compass sensors is detected. For example,if an abrupt change in the orientation of the sensors is detected whenthe vehicle is stopped or moving at or below a threshold speed (such asat or below about 10 mph or thereabouts), the control may determine thatthe abrupt change may be due to an adjustment of the mirror head orreflective element, and thus may enter the rapid and aggressivecalibration mode. Alternately, if the vehicle speed is detected (such asvia a wheel speed sensor or the like) to be above a threshold speed(such as at or above about 60 mph or thereabouts), any change in thesensed direction may be determined to be a change in vehicle direction,since it is not likely that a driver would typically adjust the mirrorposition while driving at highway speeds.

Thus, when a mirror adjustment is detected that is within the expectedrange and/or time so as to be indicative of an adjustment of the mirrorhead/reflective element by the driver of the vehicle to adjust his orher field of view rearward through the rear window of the vehicle, thecompass system of the present invention may enter the aggressivecalibration mode and begin looking for cardinal directional headings(such as North, South, East or West), such as three or more of thecardinal directional points. The compass system may distinguish betweendeviations or signatures or patterns that are indicative of anomaliesand signatures or patterns that are indicative of normal mirroradjustments by the driver and may enter the calibration mode when amirror adjustment is detected.

The compass system may remain in the aggressive calibration mode for anaggressive calibration period. The aggressive calibration period maycontinue until, for example, the three cardinal points or more or lessare detected so that the compass system is again consideredrecalibrated. Optionally, and desirably, the aggressive calibrationperiod may terminate even if the compass system has not yet sensed threeor more cardinal points, such as after a predetermined or thresholdperiod of time has elapsed since detection of the adjustment, or afterthe ignition cycle is terminated or the ignition is turned off, andbefore detection of the third cardinal point, so that the compass systemdoes not remain in the aggressive calibration mode for an excessiveperiod of time. Because it is possible that the compass system may pickup an anomaly during the aggressive calibration mode (such as, forexample, if the compass system detects the true North and West cardinalpoints, but detects an anomaly and erroneously considers the anomaly tobe the East cardinal point), and thus may use the false signal andresult in a premature exit of the calibration mode and an erroneousdirectional heading indication, it is desirable that the compass systemreturn to the aggressive calibration mode at the onset of each ignitioncycle, and/or the next ignition cycle following the detection of themirror adjustment and aggressive calibration mode. Desirably, thecompass system may initiate the aggressive calibration mode at the onsetof each ignition cycle, and the compass system may remain in theaggressive calibration mode until three cardinal points (or more or lessas desired) are detected or for a predetermined period of time followingthe ignition activation or when the ignition cycle is terminated.

Optionally, if an abrupt change upward or downward (or pivoting about agenerally horizontal axis) is detected, the control circuitry maydetermine that such an adjustment is indicative of toggling or flippingthe mirror reflective element between the daytime and nighttimeorientations, and may account for the 4½ degree (or thereabouts,depending on the particular mirror application) change or adjustment viasoftware compensation. Preferably, in such an embodiment, the nominalcondition or orientation of the compass sensor is met when the mirrorreflective element is at the daytime position or orientation. Thedetermination of the downward or upward movement of the mirror assemblymay be made irrespective of the vehicle speed, since such an adjustment(the flipping or toggling of the reflective element between the daytimeand nighttime positions) may often occur while the driver is driving thevehicle at higher speeds.

The compass display 22 may provide a display region at the reflectiveelement 16 which includes ports or portions, which may comprise icons,characters or letters or the like representative of only the cardinaldirectional points, such as, for example, the characters N, S, E, W,formed or etched in the reflective film coating of the reflectiveelement (and forming a transparent window therein), such as viatechniques such as disclosed in commonly assigned U.S. Pat. No.4,882,565, issued to Gallmeyer on Nov. 21, 1989, and such as describedin Ser. No. 10/456,599, filed Jun. 6, 2003 by Weller et al. for INTERIORREARVIEW MIRROR SYSTEM WITH COMPASS, now U.S. Pat. No. 7,004,593.Optionally, however, reflective element may comprise a transflective ordisplay on demand (DOD) reflective element, and the compass display maybe a display on demand (DOD) type of display, such as disclosed incommonly assigned U.S. Pat. Nos. 6,690,268; 5,668,663 and 5,724,187, andU.S. patent application Ser. No. 10/054,633, filed Jan. 22, 2002 byLynam et al. for VEHICULAR LIGHTING SYSTEM, now U.S. Pat. No. 7,195,381,the entire disclosures of which are hereby incorporated by referenceherein, without affecting the scope of the present invention.

The display may include a plurality of illumination sources, such aslight emitting diodes and such as blue light emitting diodes, such as anOSRAM LBT673-M2N2-35 light emitting diode or the like, which areoperable to illuminate one or more ports or regions or appropriatecharacters or letters (or through the transflective DOD reflectiveelement) to indicate the direction in which the vehicle is driving, suchas described in Ser. No. 10/456,599, filed Jun. 6, 2003 by Weller et al.for INTERIOR REARVIEW MIRROR SYSTEM WITH COMPASS, now U.S. Pat. No.7,004,593. The display ports or characters of the display may includeonly the four cardinal directional points (such as, for example, thecharacters N, S, E, W) formed or etched in the reflective film coatingof the reflective element (and forming a transparent window therein), ormay include eight directional points, such as the four cardinaldirectional points and the four intercardinal points (such as, forexample, the characters N, NE, E, SE, S, SW, W, NW), without affectingthe scope of the present invention.

The reflective element 16 may also include a port or aperture or hole inthe center area or region of the display area (or, as discussed above,may comprise a transflective or DOD reflective element) to accommodate aphoto detector or sensor (not shown), such as a photo transistor, aphoto resistor, a photo diode or the like, which may be operable tosense the ambient light levels surrounding the mirror assembly or thelight from headlights of vehicles rearward of the subject vehicle. Thephotosensor may be positioned or mounted on the printed circuit boardand may be positioned, aligned and directed to receive illuminationthrough the aperture or hole in the reflective element coating at thedisplay region or elsewhere on the reflective element or the casing(such as through an opening formed in a wall of the casing immediatelyadjacent to the location of the photosensor). The photosensor may detectthe ambient light levels generally surrounding the mirror assembly toprovide for dimming of the output of the display in darkened lightingconditions, such as at nighttime conditions, in order to reduce theintensity of the display to reduce glare and distraction and annoyanceto the driver of the vehicle. Optionally, such dimming of the displaymay be performed in response to an instrument panel dimming system ofthe vehicle, without affecting the scope of the present invention.

Optionally, the magnetoresponsive compass sensor or circuitry responsiveto the Earth's magnetic field may be operable in conjunction with theglobal positioning system of the vehicle to provide directional headingdata to the global positioning system, such as disclosed in U.S. patentapplication Ser. No. 10/422,378, filed Apr. 24, 2003 by Schofield forIMAGING SYSTEM FOR VEHICLE, now U.S. Pat. No. 6,946,978, and/or Ser. No.10/456,599, filed Jun. 6, 2003 by Weller et al. for INTERIOR REARVIEWMIRROR SYSTEM WITH COMPASS, now U.S. Pat. No. 7,004,593, which arehereby incorporated herein by reference. The compass sensor circuitrymay provide such directional heading data to assist the globalpositioning system in maintaining tracking of the location of thevehicle, such as between waypoints or the like, when the satellitesignal to the global positioning system is interrupted, such as mayoccur in cities between tall buildings (often referred to as “urbancanyons”) or the like. Other vehicle movement data may also be provided,such as vehicle speed data or vehicle odometer data or the like, tofurther assist in determining and tracking the location of the vehiclein situations where the satellite communication to the globalpositioning system of the vehicle may be temporarily interrupted orcompromised. Optionally, an imaging system (such as described in U.S.patent application Ser. No. 10/422,378, filed Apr. 24, 2003 by Schofieldfor IMAGING SYSTEM FOR VEHICLE, now U.S. Pat. No. 6,946,978, which ishereby incorporated herein by reference) may be used to further assistin determining and tracking the location of the vehicle in situationswhere the satellite communication to the global positioning system maybe temporarily interrupted or compromised.

Optionally, the printed circuit board of the compass or mirror system(such as a printed circuit board of a compass module or pod or a printedcircuit board of the mirror assembly) of the present invention mayinclude another display element along or partially along an edge of theboard and may include one or more user-actuatable controls or buttonsnear or adjacent to the display element. The display element may be anytype of display, such as a vacuum fluorescent (VF) display, a lightemitting diode (LED) display, an electroluminescent (EL) display, aliquid crystal display (LCD), a video screen display or the like, andmay be operable to display various information (as discrete characters,icons or the like, or in a multi-pixel manner) to the driver of thevehicle, such as passenger side inflatable restraint (PSIR) information,tire pressure status, and/or the like. The buttons may be for actuatingor controlling various accessories or controls or components, associatedwith the vehicle, such as for a compass calibration setting or zonesetting, a telematics actuation, a garage door opener, an electronictoll control (such as disclosed in U.S. Pat. No. 6,690,268, which ishereby incorporated herein by reference), and/or other accessories orsystems or functions or the like, or may be for switching the displaybetween various functions or modes, without affecting the scope of thepresent invention. The mirror casing may include appropriate openings,such that the display element is visible through one opening, while thebuttons or controls may partially protrude through other correspondingopenings when an appropriate circuit board is installed within themirror casing.

Optionally, the mirror assembly and/or a mounting base of the mirrormounting assembly may include or incorporate an electrical accessory orelement or circuitry that may be electrically connected to acorresponding electrical accessory or element or circuitry within themirror casing. For example, and with reference to FIG. 7, a mirrorassembly 110 may include an essentially all-polymeric or plasticmounting assembly 112 having a mounting base 124 that houses or containsan electrical element or circuitry or sensor 132, such as a compasssensor, such as a magneto-responsive sensor, such as a magneto-resistivesensor, a magneto-capacitive sensor, a magneto-inductive sensor, aflux-gate sensor or a Hall-effect sensor or the like. The sensor 132 maybe positioned at and within the molded base portion 126 a so that thesensor is substantially fixedly positioned within the vehicle when themounting base is attached to the mounting button or structure of thevehicle, such as described in U.S. patent application Ser. No.11/226,628, filed Sep. 14, 2005, which is hereby incorporated herein byreference. The sensor 132 may include a lead or wire or wires 134 with aconnector 134 a, such as a multi-pin plug or socket or the like, at anend thereof for connecting to a corresponding connector or plug orsocket 130 b of electrical conductors 130 of support arm 122. Thesupport arm 122 and electrical conductors 128, connectors 130 a, 130 b,mirror housing or casing 118 and socket 120 of mirror assembly 110 mayutilize aspects of the mirror assemblies described in U.S. patentapplication Ser. No. 11/226,628, filed Sep. 14, 2005, which are herebyincorporated herein by reference.

Mounting base 124 may be molded or formed to define the base portion 126a and a socket portion 124 a for receiving ball member 122 b of supportarm 122. The base portion 126 a may be molded over and at leastpartially around a metallic insert 126 b. Base portion 126 a may bemolded or formed with a cavity 126 c and/or passageway for receiving thesensor or wire, or may be overmolded over and at least partially aroundthe sensor and/or wire. The wire 134 comprises a flying lead or flexiblelead that extends from the base portion 126 a to the connector orterminals at the support arm 122, and includes sufficient slack orflexibility to accommodate pivotal movement or articulation of thesupport arm relative to the socket 124 a of mounting base 124. The otherconnector 130 a (at ball member 122 a received in socket 120 (which maybe formed at the casing or at a toggle member or attachment or backplate of the mirror)) may connect to a corresponding connector at acircuit board or electrical element or the like at the mirror casing,such as to circuitry on a circuit board at the reflective element or thelike. The electrical element at or in the mirror casing may includecontrols or display circuitry and elements that are associated with orincorporated in a compass system and/or display system of the mirrorassembly.

The accessory or sensor (or other electrical component or circuitry)thus may be positioned or located at or within the plastic moldedmounting base of the mirror assembly. The accessory thus is positionedgenerally along the longitudinal axis of the mounting arm, and generallybetween the ball member 122 b and the mounting base/mounting button atthe windshield when the mirror assembly is installed in a vehicle, andnot substantially above or below the mounting base (such as in a pod orgondola or module located above or below the mirror assembly) such as istypically done in known mirror assemblies. By positioning the accessorygenerally along the longitudinal axis of the support arm or generallyalong the z-axis (the axis along the vehicle and normal to the cross caror x-axis and the vertical or y-axis), the accessory is locatedgenerally between the windshield and the mirror casing and reflectiveelement when the mirror assembly is installed in the vehicle, and doesnot extend substantially above or below or to either side of the mirrorwhen the mirror assembly is installed in the vehicle. The mounting basethus may house or contain the accessory in a location that does notinterfere with the forward field of view of the driver of the vehicle.The mirror assembly of the present invention thus may provide a fixedsensor with double ball movement or articulation, and with reducedinterference with the forward field of view by the driver of thevehicle.

Optionally, the electrical accessory or circuitry housed or containedwithin the mounting base may comprise a compass sensor that is part of acompass system and/or display of the mirror assembly and/or vehicle.Note that the magneto-responsive sensor used with the mirror assemblymay comprise a magneto-responsive sensor, such as a magneto-resistivesensor such as the types disclosed in U.S. Pat. Nos. 5,255,442;5,632,092; 5,802,727; 6,173,501; 6,427,349; and 6,513,252 (which arehereby incorporated herein by reference), or a magneto-inductive sensor,such as described in U.S. Pat. No. 5,878,370 (which is herebyincorporated herein by reference), or a magneto-impedance sensor, suchas the types described in PCT Publication No. WO 2004/076971 A2,published Sep. 10, 2004 (which is hereby incorporated herein byreference), or a Hall-effect sensor, such as the types described in U.S.Pat. Nos. 6,278,271; 5,942,895 and 6,184,679 (which are herebyincorporated herein by reference). The sensor circuitry and/or thecircuitry in the mirror housing and associated with the sensor mayinclude processing circuitry. For example, a printed circuit board mayinclude processing circuitry which may include compensation methods suchas those described in U.S. Pat. Nos. 4,546,551; 5,699,044; 4,953,305;5,576,687; 5,632,092; 5,677,851; 5,708,410; 5,737,226; 5,802,727;5,878,370; 6,087,953; 6,173,508; 6,222,460; and 6,642,851, which are allhereby incorporated herein by reference. The compass sensor may beincorporated in or associated with a compass system and/or displaysystem for displaying a directional heading of the vehicle to thedriver, such as a compass system of the types described in U.S. Pat.Nos. 5,924,212; 4,862,594; 4,937,945; 5,131,154; 5,255,442; and/or5,632,092, and/or U.S. patent application Ser. No. 10/456,599, filedJun. 6, 2003 by Weller et al. for INTERIOR REARVIEW MIRROR SYSTEM WITHCOMPASS, now U.S. Pat. No. 7,004,593; and/or Ser. No. 11/029,695, filedJan. 5, 2005 by Lindahl et al. for MIRROR ASSEMBLY, now U.S. Pat. No.7,253,723, and/or PCT Application No. PCT/US2004/015424, filed May 18,2004 by Donnelly Corp. et al. for MIRROR ASSEMBLY FOR VEHICLE, andpublished on Dec. 2, 2004, as International Publication No. WO2004/103772, and/or U.S. provisional application Ser. No. 60/636,931,filed Dec. 17, 2004, which are all hereby incorporated herein byreference.

Optionally, the sensor may comprise a two-axis sensor (comprising twomagneto-responsive sensor elements disposed at a fixed angle relative toeach other, such as, preferably, orthogonally to each other, anddisposed in the cavity 126 c generally parallel to the floor plane ofthe vehicle so as to be sensitive to the horizontal component of theEarth's magnetic field), or the sensor may comprise a three-axis sensor(comprising two magneto-responsive sensor elements disposed orthogonallyto each other and disposed in the cavity, and a third magneto-responsivesensor element at a right angle (approximately ninety degrees) to thetwo sensor elements and disposed in the cavity, so that the three-axissensor is sensitive to the horizontal component and to the verticalcomponent of the Earth's magnetic field), without affecting the scope ofthe present invention. The sensor may be arranged at a desired angle toprovide enhanced sensing in the horizontal directions when the mirrorassembly is installed in the vehicle. For example, aspects ofconstructions such as are disclosed in U.S. Pat. Nos. 6,140,933 and6,928,366, which are hereby incorporated herein by reference, may beutilized.

Optionally, an integrated automotive “compass-on-a-chip” may be disposedin the cavity of the mounting base and may comprise at least twomagneto-responsive sensor elements (preferably Hall effect sensorsestablished on the semiconductor substrate, preferably a siliconsubstrate, in the same VLSI chip/circuitry manufacturing process, usingchip manufacturing processing means as known in the ASIC art),associated A/D and D/A converters, associated microprocessor(s) andmemory, associated signal processing and filtering, associated displaydriver and associated LIN/CAN BUS interface and the like, all (or asub-set thereof) created or disposed onto a semiconductor substrate,such as a silicon substrate (such as using CMOS technology), andconstituting an ASIC chip, which is small (preferably less thanapproximately a two square centimeter area, more preferably less thanapproximately a 1.5 square centimeter area, and most preferably lessthan approximately a one square centimeter area or thereabouts) andreadily packagable into the cavity. Thus, power (such as 12 volts orthereabouts, such as from the vehicle power source or the like) may besupplied to the ASIC chip and the ASIC chip may include all orsubstantially all of the circuitry for operation when the power sourceis connected to the ASIC chip.

Optionally, and preferably, such a compass-on-a-chip ASIC may alsoinclude the hardware and software required to receive an output from atemperature sensor (such as a thermocouple or thermostat that is locatedexternal the vehicle cabin in order to sense and monitor the temperatureexternal to the vehicle) and to convert this signal to a reading indegrees Fahrenheit or Celsius, and to provide this reading via anon-chip temperature display driver and/or via a BUS protocol or via anon-chip wireless transmitter or the like to a digital or other type oftemperature display so that the driver and/or occupants of the vehiclecan view the temperature being measured (such as the temperatureexternal the vehicle and/or the temperature within the vehicle cabin).Thus, for example, a monolithic compass/temp-on-a-chip ASIC may bedisposed in the likes of a mirror mount or within the mirrorhead/housing of an interior rearview mirror assembly, and it may provideboth the external temperature readout and a compass direction headingreadout to an information display at the mirror head/housing (orelsewhere in the vehicle, such as the instrument panel/cluster or at anoverhead console or accessory module or the like). Optionally, such achip or circuit board or circuitry may also or otherwise comprise ECdriver circuitry for controlling/driving an electro-optic orelectrochromic reflective element or cell, such as by utilizing aspectsof the EC driver-on-a-chip such as described in U.S. patent applicationSer. No. 11/201,661, filed Aug. 11, 2005 by DeWard et al. for ACCESSORYMODULE FOR VEHICLE, now U.S. Pat. No. 7,480,149, which is herebyincorporated herein by reference.

Optionally, the compass ASIC chip and/or compass sensor may be disposedat or in an exterior rearview mirror assembly of the vehicle (whichtypically utilizes a plastic housing). Such a location may locate thecompass chip and compass sensor outside of the magnetic anomalies of thevehicle and at a location where the compass sensor may be lesssusceptible to or less effected by the windshield wipers of the vehicleor other accessories or metal of the vehicle. Optionally, and regardlessof whether the compass chip is located behind the mirror reflectorelement or at the mirror mount or at an exterior mirror assembly of thevehicle or elsewhere in the vehicle, the display associated with thecompass chip may be located at the reflector element or elsewhere in thevehicle, such as at the mirror mount or at an accessory module orwindshield electronics module or console or the like of the vehicle.

Optionally, the printed circuit board, or the mirror assembly (or thecompass module or an accessory module associated with the mirrorassembly), may include other accessories, such as an image sensor (suchas a video camera, such as a CMOS imaging array sensor, a CCD sensor orthe like, such as the types of imaging sensors or cameras disclosed incommonly assigned, U.S. Pat. Nos. 5,550,677; 6,097,023 and 5,796,094,and/or PCT Application No. PCT/US2003/036177, filed Nov. 14, 2003 byDonnelly Corp. for IMAGING SYSTEM FOR VEHICLE, which are herebyincorporated herein by reference), a temperature sensor (such as acontact temperature sensor for measuring the temperature at or of thewindshield), an antenna, or any other sensor or device. For example, themirror assembly may include a forward facing video image sensor orsystem, which may include or may be associated with an intelligent rainsensor (such as the types disclosed in commonly assigned U.S. Pat. Nos.6,320,176; 6,353,392 and 6,313,454, which are hereby incorporated hereinby reference), an image or vision system (including an imaging sensor,such as a video camera, such as a CMOS imaging array sensor, a CCDsensor or the like, such as the types disclosed in commonly assigned,U.S. Pat. Nos. 5,550,677; 6,097,023 and 5,796,094, and U.S. patentapplication Ser. No. 10/422,378, filed Apr. 24, 2003 by Schofield forIMAGING SYSTEM FOR VEHICLE, now U.S. Pat. No. 6,946,978, which arehereby incorporated herein by reference), such as an imaging or objectdetection system or back up aid of the types described in U.S. Pat. Nos.6,757,109; 6,717,610; 6,590,719; 6,201,642; 5,929,786; and/or 5,786,772,and/or U.S. patent application Ser. No. 10/427,051, filed Apr. 30, 2003by Pawlicki et al. for OBJECT DETECTION SYSTEM FOR VEHICLE, now U.S.Pat. No. 7,038,577; and/or Ser. No. 11/239,980, filed Sep. 30, 2005 byCamilleri et al. for VISION SYSTEM FOR VEHICLE, and/or U.S. provisionalapplications, Ser. No. 60/628,709, filed Nov. 17, 2004 by Camilleri etal. for IMAGING AND DISPLAY SYSTEM FOR VEHICLE; Ser. No. 60/614,644,filed Sep. 30, 2004; and/or Ser. No. 60/618,686, filed Oct. 14, 2004 byLaubinger for VEHICLE IMAGING SYSTEM, which are hereby incorporatedherein by reference, or an intelligent headlamp controller (such as thetypes described in U.S. Pat. Nos. 5,796,094; 5,715,093; and/or6,824,281, and/or in U.S. patent application Ser. No. 10/958,087, filedOct. 4, 2004 by Schofield et al. for VEHICLE ACCESSORY MODULE, now U.S.Pat. No. 7,188,963, and/or U.S. patent application Ser. No. 11/105,757,filed Apr. 14, 2005, now U.S. Pat. No. 7,526,103; and U.S. provisionalapplications, Ser. No. 60/607,963, filed Sep. 8, 2004 by Schofield forIMAGING SYSTEM FOR VEHICLE; and Ser. No. 60/562,480, filed Apr. 15, 2004by Schofield for IMAGING SYSTEM FOR VEHICLE, which are herebyincorporated herein by reference), or an intelligent lane departurewarning system (such as the types described in U.S. patent applicationSer. No. 10/209,173, filed Jul. 31, 2001 by Schofield for AUTOMOTIVELANE CHANGE AID, now U.S. Pat. No. 6,882,287; and/or Ser. No.10/427,051, filed Apr. 30, 2003 by Pawlicki et al. for OBJECT DETECTIONSYSTEM FOR VEHICLE, now U.S. Pat. No. 7,038,577, which are herebyincorporated herein by reference), or indicator/display for a blind spotindicator or object detection system, such as the types described inU.S. provisional application Ser. No. 60/696,953, filed Jul. 6, 2005;and U.S. patent application Ser. No. 11/226,628, filed Sep. 14, 2005,which are hereby incorporated herein by reference, and/or the like. Inapplications where the mirror assembly includes or is associated with anautomatic headlamp control system, it is envisioned that the display ofthe mirror system may include or provide a high beam/low beam indicator(such as an icon or indicia indicative of the high beams beingactivated, such as a blue headlamp indicia or the like) to indicate thestatus of the high beams of the vehicle to the driver or occupant of thevehicle.

Optionally, the mirror assembly or compass or accessory or electronicmodule of the present invention may include one or more displays, suchas a text display, an icon display, a display on demand (DOD) typedisplay (such as may be implemented with a transflective reflectiveelement, such as described in U.S. Pat. Nos. 5,668,663; 5,724,187; and6,690,268, the entire disclosures of which are hereby incorporated byreference herein), such as a video or touch screen interface display, ora video display screen, such as the types described in PCT ApplicationNo. PCT/US03/40611, filed Dec. 19, 2003 by Donnelly Corp. et al. forACCESSORY SYSTEM FOR VEHICLE, and/or U.S. patent application Ser. No.11/284,543, filed Nov. 22, 2005, now U.S. Pat. No. 7,370,983, and/orU.S. provisional applications, Ser. No. 60/630,061, filed Nov. 22, 2004by Lynam et al. for MIRROR ASSEMBLY WITH VIDEO DISPLAY; and Ser. No.60/667,048, filed Mar. 31, 2005, which are hereby incorporated herein byreference, or the like, and/or one or more sensors or other accessories,such as a biometric imager, such as for fingerprint authentication orthe like, an infrared sensor, such as a zonal temperature sensor, suchas suitable for an auto climate control, a forward facing image sensor,such as described above, a rearward facing image sensor (such as forbiometric imaging (such as for face recognition, iris recognition or thelike), seat height or position detection, drowsiness detection,safety/restraints object detection and position, emergency responseimage capture system, intrusion detection or the like), anelectromagnetic field sensor (such as the type disclosed in commonlyassigned U.S. Pat. No. 6,768,420, which is hereby incorporated herein byreference).

Optionally, and for a mirror assembly having a slideout orextendable/retractable display, such as a video slideout display or thelike (such as the types described in PCT Application No. PCT/US03/40611,filed Dec. 19, 2003 by Donnelly Corp. et al. for ACCESSORY SYSTEM FORVEHICLE, and/or U.S. patent application Ser. No. 11/284,543, filed Nov.22, 2005, now U.S. Pat. No. 7,370,983, and/or U.S. provisionalapplications, Ser. No. 60/630,061, filed Nov. 22, 2004 by Lynam et al.for MIRROR ASSEMBLY WITH VIDEO DISPLAY; and Ser. No. 60/667,048, filedMar. 31, 2005, which are hereby incorporated herein by reference), thedisplay may be operable or activatable when in its retracted orpartially retracted position so as to provide display information, suchas directional heading information or temperature information or othervehicle information or the like, that is viewable through the reflectiveelement when the display is at least partially retracted. As describedin the above referenced applications, such a slideout display isextended to display information to the driver of the vehicle and may beretracted when such information is not being displayed. When retracted,the display typically is deactivated and located behind the mirrorreflector. In such a retracted or partially retracted position, thedisplay element or screen is positioned at least partially at the rearof the mirror reflector element with the display element or screenfacing the rear surface of the mirror reflector element.

It is thus envisioned that the display element (such as a video displayelement or LCD element or the like) may be activated when it isretracted or at least partially retracted, so that the displayinformation or illumination emitted by the display element may beprojected through the transflective mirror reflector element for viewingat the mirror reflector element. For example, and for mirror assemblieshaving a transflective mirror reflector element, the opaque backing ofthe reflector element may have a window or aperture or display areaformed therethrough so that at least a portion of the display element,when activated in its retracted or partially retracted position, isviewable through the transflective mirror reflector at the display area.

In such an embodiment, it is desirable that there be a close orsubstantial optical coupling between the front surface of the displayelement or screen (the surface facing generally toward the driver of thevehicle when the mirror assembly is mounted in the vehicle) and the rearsurface of the mirror reflector element (the surface facing generallyaway from the driver of the vehicle when the mirror assembly is mountedin the vehicle). Preferably, the mirror assembly may include anopaquifying or shading cover or baffle element that covers the displayarea when the slideout display is extended or at least partiallyextended and not activated to provide display information at the displayarea. For example, an opaque shading element may move over the windowarea at the rear of the mirror reflector element to cover/shade/opaquifythe window/display area so that the internal components of the mirrorassembly are not viewable through the window/display area when thedisplay element is moved at least partially toward its extendedposition.

Thus, for example, a video slideout interior rearview mirror assemblycan be provided that, when the driver selects reverse gear, a back litTFT LCD screen may extend at the passenger side to display an image of ascene occurring immediately to the rear of the vehicle (such as capturedby a rear mounted camera) so that the driver may view the image during areversing maneuver to assist in reversing the vehicle. Preferably, sucha display may include a graphic overlay or other indicia or the like,such as described in U.S. patent application Ser. No. 11/284,543, filedNov. 22, 2005, now U.S. Pat. No. 7,370,983, to assist the driver inmaking the reversing maneuver. Upon the disengagement of the reversegear by the driver, the display slides in or retracts to its stowedposition. When the driver is driving the vehicle forward along a road, acompass display is viewable to the driver when he or she looks at themirror. The compass display may be derived from a compass-on-a-chipsensor that is preferably mounted within a mirror mount or alternativelywithin the mirror casing or elsewhere in the vehicle. The compassdisplay at the mirror reflector or reflective element (such as atransflective electrochromic reflective element or a transflectiveprismatic reflective element or the like) is provided by the same TFTLCD display screen or display element that is now stowed behind thereflective element and is seen through the transflective reflectiveelement. Thus, the utility and user appreciation of the slideout displayis enhanced because, when the vehicle is reversing, the display canslideout or extend to show the reversing scene and, when the display isstowed, such as during normal driving conditions, the same displayelement is used to provide an information display at the mirrorreflector.

The display and/or accessories may be associated with a communicationsystem, a speaker, a telematics module (which may include a GPS module,a wireless communication module, an human/machine interface (HMI), adisplay, such as an LED display, a dot matrix display, an alpha numericdisplay, a video display or the like, and/or a microphone, which may beoperable for speech or voice recognition, noise reduction or noisecancellation), a humidity sensor, a remote keyless entry sensor, a tirepressure monitoring system (TPMS), an electronic toll collection sensor,an intelligent headlamp control, user interface controls (such asbuttons, switches or the like for controlling various accessories of thevehicle, such as a sunroof, a communication system, lamps, securitysystems, displays or the like) or any other accessories, sensors,lights, indicators, displays or the like which may be suitable formounting or positioning at or within the interior rearview mirrorassembly or accessory module. The interior rearview mirror assemblyand/or compass or accessory module may also provide for glare reductioncharacteristics of the reflective element of the rearview mirrorassembly.

Optionally, the mirror assembly of the present invention may include oneor more other accessories at or within the mirror casing, such as one ormore electrical or electronic devices or accessories, such as antennas,including global positioning system (GPS) or cellular phone antennas,such as disclosed in U.S. Pat. No. 5,971,552, a communication module,such as disclosed in U.S. Pat. No. 5,798,688, transmitters and/orreceivers, such as a garage door opener or the like, a digital network,such as described in U.S. Pat. No. 5,798,575, a memory mirror system,such as disclosed in U.S. Pat. No. 5,796,176, a hands-free phoneattachment, a video device for internal cabin surveillance and/or videotelephone function, such as disclosed in U.S. Pat. Nos. 5,760,962 and/or5,877,897; and/or PCT Application No. PCT/US03/40611, filed Dec. 19,2003 by Donnelly Corp. et al. for ACCESSORY SYSTEM FOR VEHICLE, and/orU.S. patent application Ser. No. 11/284,543, filed Nov. 22, 2005, nowU.S. Pat. No. 7,370,983, and/or U.S. provisional applications, Ser. No.60/630,061, filed Nov. 22, 2004 by Lynam et al. for MIRROR ASSEMBLY WITHVIDEO DISPLAY; and Ser. No. 60/667,048, filed Mar. 31, 2005, a remotekeyless entry receiver or system or circuitry and/or a universal garagedoor opening system or circuitry (such as the types disclosed in U.S.Pat. Nos. 6,396,408; 6,362,771; 5,798,688 and 5,479,155, and/or U.S.patent application Ser. No. 10/770,736, filed Feb. 3, 2004 byBaumgardner et al. for GARAGE DOOR OPENING SYSTEM FOR VEHICLE, now U.S.Pat. No. 7,023,322), a remote keyless entry receiver, lights, such asmap reading lights or one or more other lights or illumination sources,such as disclosed in U.S. Pat. Nos. 6,690,268; 5,938,321; 5,813,745;5,820,245; 5,673,994; 5,649,756; 5,178,448; 5,671,996; 4,646,210;4,733,336; 4,807,096; 6,042,253; and/or 5,669,698, and/or U.S. patentapplication, Ser. No. 10/054,633, filed Jan. 22, 2002 by Lynam et al.for VEHICULAR LIGHTING SYSTEM, now U.S. Pat. No. 7,195,381, microphones,such as disclosed in U.S. Pat. Nos. 6,243,003; 6,278,377; and/or6,420,975; and/or PCT Application No. PCT/US03/30877, filed Oct. 1,2003, speakers, a tire pressure monitoring system, such as the typesdisclosed in U.S. Pat. Nos. 6,294,989; 6,445,287; and/or 6,472,979,and/or U.S. patent application Ser. No. 11/232,324, filed Sep. 21, 2005,now U.S. Pat. No. 7,423,522, and U.S. provisional application Ser. No.60/611,796, filed Sep. 21, 2004 by O'Brien for TIRE PRESSURE ALERTSYSTEM, a navigation system, such as described in U.S. Pat. No.6,477,464, and U.S. patent application Ser. No. 10/456,599, filed Jun.6, 2003 by Weller et al. for INTERIOR REARVIEW MIRROR SYSTEM WITHCOMPASS, now U.S. Pat. No. 7,004,593; Ser. No. 10/287,178, filed Nov. 4,2002 by McCarthy et al. for NAVIGATION SYSTEM FOR A VEHICLE, now U.S.Pat. No. 6,678,614; Ser. No. 10/645,762, filed Aug. 20, 2003 by Tayloret al. for VEHICLE NAVIGATION SYSTEM FOR USE WITH A TELEMATICS SYSTEM,now U.S. Pat. No. 7,167,796; and Ser. No. 10/422,378, filed Apr. 24,2003, now U.S. Pat. No. 6,946,978; and/or PCT Application No.PCT/US03/40611, filed Dec. 19, 2003 by Donnelly Corp. et al. forACCESSORY SYSTEM FOR VEHICLE, a seat occupancy detector, a vehicleoccupancy detector, such as the types described in U.S. Pat. No.6,768,420 and/or PCT Application No. PCT/US05/42504, filed. Nov. 22,2005 by Donnelly Corp. et al. for OCCUPANT DETECTION SYSTEM FOR VEHICLE;and/or U.S. provisional application Ser. No. 60/630,364, filed Nov. 22,2004 by Wåhlström for OCCUPANT DETECTION SYSTEM FOR VEHICLE, a tripcomputer, an ONSTAR® system and/or the like (with all of theabove-referenced patents and patent applications and PCT applicationsand provisional applications being commonly assigned to Donnelly Corp.,and with the disclosures of the referenced patents and patentapplications and PCT applications and provisional applications beinghereby incorporated herein by reference in their entireties). Theaccessory or accessories may be positioned at or within the mirrorcasing and may be included on or integrated in a printed circuit boardpositioned within the mirror casing, such as along a rear surface of thereflective element or elsewhere within a cavity defined by the casing,without affecting the scope of the present invention.

The interior rearview mirror assembly and/or an associated accessorymodule may also include user interface controls, such as buttons,switches or the like, displays, indicators, microphones, speakers or thelike. Some of these may be provided at or along a display or interfacearea at or above the mirror. Optionally, the mirror assembly may includea user actuatable input or inputs to activate or deactivate or adjustone or more accessories of the mirror assembly or accessory module orconsole or of the vehicle. The inputs may be positioned at the mirrorcasing or bezel portion of the mirror assembly where they may be readilyaccessible by the driver or occupant of the vehicle. The inputs maycomprise push buttons or the like or touch sensitive elements or sensorsor proximity sensors or the like that may be selectively touched ordepressed or approached to activate/deactivate/adjust the accessory oraccessories, as discussed below. The inputs may utilize aspects such asthose described in PCT Application No. PCT/US2003/036177, filed Nov. 14,2003 by Donnelly Corp. for IMAGING SYSTEM FOR VEHICLE and/or PCTApplication No. PCT/US04/015424, filed May 18, 2004 by Donnelly Corp. etal. for MIRROR ASSEMBLY FOR VEHICLE, published Dec. 2, 2004 as PCTPublication No. WO 2004/103772 A2, which are hereby incorporated hereinby reference, or may utilize aspects of touch sensitive elements of thetypes described in U.S. Pat. Nos. 5,594,222; 6,001,486; 6,310,611;6,320,282; and 6,627,918, and U.S. patent application Ser. No.09/817,874, filed Mar. 26, 2001 by Quist et al. for INTERACTIVEAUTOMOTIVE REARVISION SYSTEM, now U.S. Pat. No. 7,224,324, which arehereby incorporated herein by reference, or may comprise proximitysensors of the types described in U.S. Pat. Publication No.2002/0044065, published Apr. 18, 2002 by Quist et al. for INTERACTIVEAUTOMOTIVE REARVISION SYSTEM, now U.S. Pat. No. 7,224,324; and/or U.S.patent application Ser. No. 11/284,543, filed Nov. 22, 2005, now U.S.Pat. No. 7,370,983; Ser. No. 10/933,842, filed Sep. 3, 2004, now U.S.Pat. No. 7,249,860; and/or Ser. No. 10/956,749, filed Oct. 1, 2004, nowU.S. Pat. No. 7,446,924; and/or PCT Application No. PCT/US03/40611,filed Dec. 19, 2003 by Donnelly Corp. et al. for ACCESSORY SYSTEM FORVEHICLE, and/or U.S. provisional applications, Ser. No. 60/630,061,filed Nov. 22, 2004 by Lynam et al. for MIRROR ASSEMBLY WITH VIDEODISPLAY; and Ser. No. 60/667,048, filed Mar. 31, 2005, which are herebyincorporated herein by reference, or may comprise inputs molded withinthe bezel of the mirror assembly, such as described in U.S. patentapplication Ser. No. 11/029,695, filed Jan. 5, 2005, now U.S. Pat. No.7,253,723, and U.S. provisional applications, Ser. No. 60/535,559, filedJan. 9, 2004 by Lindahl for MIRROR ASSEMBLY; and Ser. No. 60/553,517,filed Mar. 16, 2004 by Lindahl et al. for MIRROR ASSEMBLY, which arehereby incorporated herein by reference, or may comprise membrane typeswitches, such as described in U.S. patent application Ser. No.11/140,396, filed May 27, 2005, now U.S. Pat. No. 7,360,932, and U.S.provisional applications, Ser. No. 60/575,904, filed Jun. 1, 2004 byUken for MIRROR ASSEMBLY FOR VEHICLE; and/or Ser. No. 60/624,320, filedNov. 2, 2004 by Uken for MIRROR ASSEMBLY FOR VEHICLE, which are herebyincorporated herein by reference, or other types of switches or buttonsor inputs, such as, for example, inputs of the types described in U.S.provisional applications, Ser. No. 60/719,482, filed Sep. 22, 2005; andSer. No. 60/690,401, filed Jun. 14, 2005, which are hereby incorporatedherein by reference, and/or the like, without affecting the scope of thepresent invention.

The accessory or accessories may be positioned at or within the mirrorcasing and may be included on or integrated in the printed circuit boardpositioned within the mirror casing, such as along a rear surface of thereflective element or elsewhere within a cavity defined by the casing,without affecting the scope of the present invention. The useractuatable inputs described above may be actuatable to control and/oradjust the accessories of the mirror assembly/system and/or an overheadconsole and/or an accessory module/windshield electronics module and/orthe vehicle. The connection or link between the controls and the systemsor accessories may be provided via vehicle electronic or communicationsystems and the like, and may be connected via various protocols ornodes, such as Bluetooth™, SCP, UBP, J1850, CAN J2284, Fire Wire 1394,MOST, LIN, FlexRay™, Byte Flight and/or the like, or other vehicle-basedor in-vehicle communication links or systems (such as WIFI and/or IRDA)and/or the like, depending on the particular application of themirror/accessory system and the vehicle. Optionally, the connections orlinks may be provided via wireless connectivity or links, such as via awireless communication network or system, such as described in U.S.patent application Ser. No. 10/456,599, filed Jun. 6, 2003 by Weller etal. for INTERIOR REARVIEW MIRROR SYSTEM WITH COMPASS, now U.S. Pat. No.7,004,593, which is hereby incorporated herein by reference, withoutaffecting the scope of the present invention.

Optionally, the interior rearview mirror assembly or an associatedaccessory module or windshield electronics module or console may includea network bus, such as a CAN bus or a LIN bus, such as disclosed in U.S.Pat. No. 6,291,905, which is hereby incorporated herein by reference.The network bus may be operable to communicate with other systems of thevehicle, such as with accessories or elements of an accessory module,such as an accessory module of the type disclosed in commonly assignedU.S. Pat. Nos. 6,824,281; 6,243,003; 6,278,377 and 6,420,975; U.S.patent application Ser. No. 10/054,633, filed Jan. 22, 2002 by Lynam etal. for VEHICULAR LIGHTING SYSTEM, now U.S. Pat. No. 7,195,381; U.S.patent application Ser. No. 10/958,087, filed Oct. 4, 2004 by Schofieldet al. for VEHICLE ACCESSORY MODULE, now U.S. Pat. No. 7,188,963; and/orInternational Publication No. WO 01/64481, published Sep. 7, 2001, whichare all hereby incorporated herein by reference.

Optionally, the mirror assembly may comprise an electro-optic orelectrochromic mirror assembly and may include an electro-optic orelectrochromic reflective element. The electrochromic mirror element ofthe electrochromic mirror assembly may utilize the principles disclosedin commonly assigned U.S. Pat. Nos. 6,690,268; 5,140,455; 5,151,816;6,178,034; 6,154,306; 6,002,544; 5,567,360; 5,525,264; 5,610,756;5,406,414; 5,253,109; 5,076,673; 5,073,012; 5,117,346; 5,724,187;5,668,663; 5,910,854; 5,142,407 and/or 4,712,879, which are herebyincorporated herein by reference, and/or as disclosed in the followingpublications: N. R. Lynam, “Electrochromic Automotive Day/NightMirrors”, SAE Technical Paper Series 870636 (1987); N. R. Lynam, “SmartWindows for Automobiles”, SAE Technical Paper Series 900419 (1990); N.R. Lynam and A. Agrawal, “Automotive Applications of ChromogenicMaterials”, Large Area Chromogenics: Materials and Devices forTransmittance Control, C. M. Lampert and C. G. Granquist, EDS., OpticalEngineering Press, Wash. (1990), which are hereby incorporated byreference herein; and/or as described in U.S. patent application Ser.No. 10/054,633, filed Jan. 22, 2002 by Lynam et al. for VEHICULARLIGHTING SYSTEM, now U.S. Pat. No. 7,195,381, which are herebyincorporated herein by reference. The mirror assembly may include one ormore other displays, such as the types disclosed in U.S. Pat. Nos.5,530,240 and/or 6,329,925, which are hereby incorporated herein byreference, and/or display-on-demand transflective type displays, such asthe types described in U.S. Pat. Nos. 5,668,663; 5,724,187 and/or6,690,268, and/or in U.S. patent application Ser. No. 10/054,633, filedJan. 22, 2002 by Lynam et al. for VEHICULAR LIGHTING SYSTEM, now U.S.Pat. No. 7,195,381; Ser. No. 11/021,065, filed Dec. 23, 2004, now U.S.Pat. No. 7,255,451; Ser. No. 11/226,628, filed Sep. 14, 2005; and/orSer. No. 10/538,724, filed Jun. 13, 2005; Ser. No. 10/528,269, filedMar. 17, 2005, now U.S. Pat. No. 7,274,501; and/or Ser. No. 10/533,762,filed May 4, 2005, now U.S. Pat. No. 7,184,190, and/or PCT ApplicationNo. PCT/US03/29776, filed Sep. 9, 2003 by Donnelly Corp. et al. forMIRROR REFLECTIVE ELEMENT ASSEMBLY, which are all hereby incorporatedherein by reference, or ultra small information displays, such as aredisclosed in U.S. patent application Ser. No. 10/225,851, filed Aug. 22,2002 by Burgner for VEHICLE INFORMATION DISPLAY, now U.S. Pat. No.6,847,487, the entire disclosure of which is hereby incorporated byreference herein. The thicknesses and materials of the coatings on thesubstrates, such as on the third surface of the reflective elementassembly, may be selected to provide a desired color or tint to themirror reflective element, such as a blue colored reflector, such as isknown in the art and such as described in U.S. Pat. Nos. 5,910,854 and6,420,036, and in U.S. patent application Ser. No. 10/528,269, filedMar. 17, 2005, now U.S. Pat. No. 7,274,501, and in PCT Application No.PCT/US03/29776, filed Sep. 9, 2003 by Donnelly Corp. et al. for MIRRORREFLECTIVE ELEMENT ASSEMBLY, which are all hereby incorporated herein byreference. The coatings and/or encapsulants and the like may be selectedto provide the desired appearance and features for the reflectiveelement assembly, such as utilizing the principles described in U.S.patent application Ser. No. 11/021,065, filed Dec. 23, 2004, now U.S.Pat. No. 7,255,451; and U.S. provisional applications, Ser. No.60/563,342, filed Apr. 19, 2004 by Bareman et al. for METHOD OFMANUFACTURING ELECTRO-OPTIC MIRROR CELL; and/or Ser. No. 60/629,926,filed Nov. 22, 2004 by McCabe et al. for METHOD OF MANUFACTURINGELECTRO-OPTIC MIRROR CELL, which are hereby incorporated herein byreference.

It is further envisioned that the interior rearview mirror assembly mayinclude a transflective one way mirror element, such as disclosed incommonly assigned U.S. patent application Ser. No. 10/054,633, filedJan. 22, 2002 by Lynam et al. for VEHICULAR LIGHTING SYSTEM, now U.S.Pat. No. 7,195,381, which is hereby incorporated herein by reference.Preferably, the mirror reflective element (behind which a video displayscreen may be disposed so that the image displayed is visible by viewingthrough the mirror reflective element) of the interior mirror assemblycomprises a transflective mirror reflector such that the mirrorreflective element is significantly transmitting to visible lightincident from its rear (i.e. the portion furthest from the driver in thevehicle), with at least about 15 percent transmission of lighttherethrough preferred, at least about 20 percent transmission of lighttherethrough more preferred and at least about 25 percent transmissionof light therethrough most preferred, while simultaneously, the mirrorreflective element is substantially reflective to visible light incidentfrom its front (i.e. the position closest to the driver when theinterior mirror assembly is mounted in the vehicle), with at least about60 percent reflectance of light incident thereon preferred, at leastabout 70 percent reflectance of light incident thereon more preferredand at least about 75 percent reflectance of light incident thereon mostpreferred. Preferably, a transflective electrochromic reflective mirrorelement is used (such as is disclosed in U.S. Pat. Nos. 5,668,663;5,724,187; and 6,690,268, the entire disclosures of which are herebyincorporated by reference herein) that comprises an electrochromicmedium sandwiched between two substrates.

Optionally, the mirror assembly and/or prismatic or electrochromicreflective element may include one or more displays, such as for theaccessories or circuitry described herein. The displays may be similarto those described above, or may be of types disclosed in U.S. Pat. Nos.5,530,240 and/or 6,329,925, which are hereby incorporated herein byreference, and/or may be display-on-demand or transflective typedisplays, such as the types disclosed in U.S. Pat. Nos. 6,690,298;5,668,663 and/or 5,724,187, and/or in U.S. patent application Ser. No.10/054,633, filed Jan. 22, 2002, now U.S. Pat. No. 7,195,381; Ser. No.11/226,628, filed Sep. 14, 2005 by Karner et al.; and/or Ser. No.10/993,302, filed Nov. 19, 2004, now U.S. Pat. No. 7,338,177; and/or inU.S. provisional applications, Ser. No. 60/525,952, filed Nov. 26, 2003by Lynam for MIRROR REFLECTIVE ELEMENT FOR A VEHICLE; Ser. No.60/717,093, filed Sep. 14, 2005 by Lynam; and/or Ser. No. 60/732,245,filed Nov. 1, 2005 by Weller for INTERIOR REARVIEW MIRROR ASSEMBLY WITHDISPLAY, and/or in PCT Application No. PCT/US03/29776, filed Sep. 19,2003 by Donnelly Corp. et al. for MIRROR REFLECTIVE ELEMENT ASSEMBLY,which are all hereby incorporated herein by reference. Optionally, aprismatic reflective element may comprise a display on demand ortransflective prismatic element (such as described in PCT ApplicationNo. PCT/US03/29776, filed Sep. 19, 2003 by Donnelly Corp. et al. forMIRROR REFLECTIVE ELEMENT ASSEMBLY; and/or U.S. patent application Ser.No. 10/993,302, filed Nov. 19, 2004, now U.S. Pat. No. 7,338,177, whichare all hereby incorporated herein by reference) so that the displaysare viewable through the reflective element, while the display areastill functions to substantially reflect light, in order to provide agenerally uniform prismatic reflective element even in the areas thathave display elements positioned behind the reflective element.

Optionally, the display and any associated user inputs may be associatedwith various accessories or systems, such as, for example, a tirepressure monitoring system or a passenger air bag status or a garagedoor opening system or a telematics system or any other accessory orsystem of the mirror assembly or of the vehicle or of an accessorymodule or console of the vehicle, such as an accessory module or consoleof the types described in U.S. Pat. Nos. 6,690,268; 6,672,744;6,386,742; and 6,124,886, and/or U.S. patent application Ser. No.10/739,766, filed Dec. 18, 2003 by DeLine et al. for MODULAR REARVIEWMIRROR ASSEMBLY, now U.S. Pat. No. 6,877,888; and/or Ser. No.10/355,454, filed Jan. 31, 2003 by Schofield et al. for VEHICLEACCESSORY MODULE, now U.S. Pat. No. 6,824,281, and/or PCT ApplicationNo. PCT/US03/03012, filed Jan. 31, 2003 by Donnelly Corporation forVEHICLE ACCESSORY MODULE, and/or PCT Application No. PCT/US03/40611,filed Dec. 19, 2003 by Donnelly Corporation for ACCESSORY SYSTEM FORVEHICLE, and/or PCT Application No. PCT/US04/15424, filed May 18, 2004by Donnelly Corporation et al. for MIRROR ASSEMBLY FOR VEHICLE, andpublished on Dec. 2, 2004, as International Publication No. WO2004/103772, which are hereby incorporated herein by reference.

Optionally, the mirror system or interior rearview mirror assemblyand/or compass system of the present invention may includeelectrochromic control circuitry for controlling the reflectivity of anelectrochromic mirror. The circuitry may include a rearward viewingglare detector or sensor and a forward viewing and/or downward and/orsideward viewing ambient light detector or sensor, such as described inU.S. Pat. No. 4,793,690, which is hereby incorporated herein byreference, or may include a single sensor, such as described in U.S.Pat. No. 5,193,029, which is hereby incorporated herein by reference.The output of the circuitry may control an outside electrochromic mirroras well as the interior rearview electrochromic mirror. It is furtherenvisioned that the circuitry may control an outside electrochromicmirror, while the interior rearview mirror assembly may be a prismaticmirror, without affecting the scope of the present invention.

The network bus of the interior rearview mirror assembly may then be incommunication with the reversing system of the vehicle, such that theinterior rearview mirror assembly knows when the vehicle is shifted intoreverse. The bus may then be operable to disable the electrochromicdimming of the mirror when the vehicle is in reverse, as is desired andknown in the art.

Further, automatic dimming circuitry used in the electrochromic mirrorassembly and/or in an accessory module may utilize one or more(typically two) photosensors to detect glaring and/or ambient lighting.Optionally, the mirror assembly (such as for an interior or exteriorrearview mirror assembly) may include a photo sensor or light sensor(such as the types described in U.S. Pat. Nos. 6,831,268; 6,742,904;6,737,629; 4,799,768; and 4,793,690, and U.S. patent application Ser.No. 10/456,599, filed Jun. 6, 2003 by Weller et al. for INTERIORREARVIEW MIRROR SYSTEM WITH COMPASS, now U.S. Pat. No. 7,004,593, whichare hereby incorporated herein by reference) at the rear or fourthsurface of the reflective element assembly, such that the photo sensordetects light passing through the reflective element assembly. Examplesof such configurations are described in U.S. Pat. Nos. 4,793,690;5,550,677 and 5,193,029, and U.S. patent application Ser. No.10/456,599, filed Jun. 6, 2003 by Weller et al. for INTERIOR REARVIEWMIRROR SYSTEM WITH COMPASS, now U.S. Pat. No. 7,004,593, which are allhereby incorporated herein by reference. For example, a siliconphotosensor, such as a TSL235R Light-to-Frequency converter (availablefrom Texas Advanced Optoelectronic Solutions Inc. of Plano, Tex.), maybe used as such a photosensor. Such light-to-frequency converterscomprise the combination of a silicon photodiode and acurrent-to-frequency converter on a single monolithic CMOS integratedcircuit.

Optionally, a silicon based optical sensor may provide a non-linearresponse for the electro-optic or electrochromic reflective elementdimming circuitry. Optionally, an infrared (IR) filtering thin film maybe deposited on the sensor (or may be disposed in front of the sensor)to filter or attenuate infrared radiation at the photo sensor.Optionally, the sensor may be mounted at the rear of the reflectiveelement assembly and may be mounted at a black plastic surface mountthat has a clear window, such that light leakage from non-intended lightsources is reduced and such that the environmental properties of thesensor and mounting package are substantially enhanced.

The interior rearview mirror assembly may include the bezel portion andthe casing, such as described above, or the mirror assembly may compriseother types of casings or bezel portions or the like, such as describedin U.S. Pat. Nos. 6,439,755; 4,826,289; and 6,501,387; and/or PCTApplication No. PCT/US2004/015424, filed May 18, 2004 by Donnelly Corp.et al. for MIRROR ASSEMBLY FOR VEHICLE, and published on Dec. 2, 2004,as International Publication No. WO 2004/103772; and/or U.S. patentapplication Ser. No. 10/933,842, filed Sep. 3, 2004 by Kulas et al. forINTERIOR REARVIEW MIRROR ASSEMBLY, now U.S. Pat. No. 7,249,860; and/orSer. No. 10/993,302, filed Nov. 19, 2004 by Lynam for MIRROR REFLECTIVEELEMENT FOR A VEHICLE, now U.S. Pat. No. 7,338,177, which are all herebyincorporated herein by reference, without affecting the scope of thepresent invention. For example, the mirror assembly may comprise a flushor frameless or bezelless reflective element, such as the typesdescribed in PCT Application No. PCT/US2004/015424, filed May 18, 2004by Donnelly Corp. et al. for MIRROR ASSEMBLY FOR VEHICLE, and publishedon Dec. 2, 2004, as International Publication No. WO 2004/103772; PCTApplication No. PCT/US03/35381, filed Nov. 5, 2003 by Donnelly Corp. etal. for ELECTRO-OPTIC REFLECTIVE ELEMENT ASSEMBLY; and/or in U.S. patentapplication Ser. No. 11/140,396, filed May 27, 2005, now U.S. Pat. No.7,360,932; Ser. No. 11/226,628, filed Sep. 14, 2005; Ser. No.11/021,065, filed Dec. 23, 2004, now U.S. Pat. No. 7,255,451; Ser. No.10/528,269, filed Mar. 17, 2005, now U.S. Pat. No. 7,274,501; Ser. No.10/533,762, filed May 4, 2005, now U.S. Pat. No. 7,184,190; and/or Ser.No. 10/538,724, filed Jun. 13, 2005; and/or in U.S. provisionalapplications, Ser. No. 60/563,342, filed Apr. 19, 2004 by Bareman et al.for METHOD OF MANUFACTURING ELECTRO-OPTIC MIRROR CELL; Ser. No.60/629,926, filed Nov. 22, 2004 by McCabe et al. for METHOD OFMANUFACTURING ELECTRO-OPTIC MIRROR CELL; Ser. No. 60/624,320, filed Nov.2, 2004 by Uken for MIRROR ASSEMBLY FOR VEHICLE; Ser. No. 60/681,250,filed May 16, 2005; Ser. No. 60/690,400, filed Jun. 14, 2005; Ser. No.60/695,149, filed Jun. 29, 2005; and/or Ser. No. 60/730,334, filed Oct.26, 2005 by Baur for VEHICLE MIRROR ASSEMBLY WITH INDICIA AT REFLECTIVEELEMENT, which are all hereby incorporated herein by reference.

Therefore, the present invention provides a mirror and compass systemthat positions the compass sensors within the movable head portion ofthe mirror assembly in a manner that reduces the effects of mirroradjustment on the sensor performance. The compass system may adjustprocessing in response to known movements of the mirror head tocompensate for such known movements. The compass system of the presentinvention may distinguish between deviations, signatures or patternsindicative of magnetic anomalies or stray magnetic fields or the likegenerated external to the vehicle (such as by metal bridges, subwaylines, cellular telephone towers, large metal structures and the like),and deviations, signatures or patterns indicative of mirror adjustmentsby the driver (as the driver may grasp and move the mirrorhead/reflective element to adjust his or her field of view rearwardthrough the rear window of the vehicle), and may enter the calibrationmode when a mirror adjustment is detected and distinguished orrecognized. The compass system may enter an aggressive calibration modeto calibrate the sensors when the mirror has been adjusted by a user.The commencement of the aggressive calibration mode may be effected bythe type of adjustment, vehicle speed, time elapsed since activation ofthe vehicle ignition or other activating or triggering event or thelike.

Changes and modifications in the specifically described embodiments canbe carried out without departing from the principles of the presentinvention, which is intended to be limited only by the scope of theappended claims as interpreted according to the principles of patentlaw.

1. An interior rearview mirror system for a vehicle, said interiorrearview mirror system comprising: an interior rearview mirror assemblycomprising a mirror casing and a reflective element; wherein saidreflective element provides a field of view rearward of the vehicle to adriver of the vehicle when said interior rearview mirror assembly isnormally mounted in the vehicle and is adjusted to a viewingorientation; wherein a mounting structure mounts said interior rearviewmirror assembly to an interior portion of the vehicle, and wherein saidmirror casing is adjustable by the driver of the vehicle relative to theinterior portion of the vehicle via at least one pivot element of saidmounting structure to adjust the rearward field of view of saidreflective element when said interior rearview mirror assembly isnormally mounted in the vehicle; wherein said interior rearview mirrorassembly comprises an application specific integrated compass chip; saidapplication specific integrated compass chip comprising at least twomagnetoresponsive sensing elements established on a semiconductorsubstrate; said application specific integrated compass chip furthercomprising associated circuitry commonly established with saidmagnetoresponsive sensing elements on said semiconductor substrate;wherein said application specific integrated compass chip has an area ofless than approximately two square centimeters; wherein processing of analgorithm by a microprocessor of said interior rearview mirror systemdetermines a directional heading of the vehicle responsive to a sensingof a magnetic field by said magnetoresponsive sensing elements andautomatically compensates for a deviating magnetic field; and wherein aninformation display of said interior rearview mirror assembly displaysthe directional heading of the vehicle.
 2. The interior rearview mirrorsystem of claim 1, wherein said associated circuitry comprises at leastone of (i) an A/D converter, (ii) a D/A converter and (iii) signalprocessing circuitry.
 3. The interior rearview mirror system of claim 2,wherein said associated circuitry comprises at least one of (i) memory,(ii) signal filtering circuitry, (iii) a display driver and (iv) avehicle bus interface.
 4. The interior rearview mirror system of claim3, wherein said associated circuitry comprises said microprocessor. 5.The interior rearview mirror system of claim 1, wherein saidmagnetoresponsive sensing elements and said associated circuitry arecommonly established on said semiconductor substrate using CMOStechnology.
 6. The interior rearview mirror system of claim 5, whereinsaid semiconductor substrate comprises a silicon substrate.
 7. Theinterior rearview mirror system of claim 1, wherein said applicationspecific integrated compass chip is disposed in said mirror casing andmoves in tandem with said mirror casing and said reflective element whensaid mirror casing is adjusted by the driver of the vehicle relative tothe interior portion of the vehicle.
 8. The interior rearview mirrorsystem of claim 7, wherein said application specific integrated compasschip is oriented in said mirror casing such that said magnetoresponsivesensing elements are arranged generally horizontally when said interiorrearview mirror assembly is normally mounted in a vehicle.
 9. Theinterior rearview mirror system of claim 7, wherein said applicationspecific integrated compass chip is supported by said reflectiveelement.
 10. The interior rearview mirror system of claim 7, wherein analgorithm processed by said microprocessor discerns between a change insaid sensing by said magnetoresponsive sensing elements that isindicative of an adjustment of said mirror casing by the driver of thevehicle and a change in said sensing by said magnetoresponsive sensingelements that is indicative of a change in vehicle direction, and causessaid interior rearview mirror system to enter a rapid compensating modewhen the change in said sensing by said magnetoresponsive sensingelements is indicative of an adjustment of said mirror casing by thedriver of the vehicle.
 11. The interior rearview mirror system of claim7, wherein electrical wiring providing electrical power for saidapplication specific integrated compass chip passes through said atleast one pivot element of said mounting structure.
 12. The interiorrearview mirror system of claim 11, wherein said at least one pivotelement comprises two pivot elements that are part of a double pivotmounting structure, and wherein said electrical wiring passes throughboth of said pivot elements of said double pivot mounting structure. 13.The interior rearview mirror system of claim 11, wherein the interiorportion of the vehicle comprises a mounting button attached at aninterior surface of the windshield of the vehicle and wherein saidmounting structure comprises a mount for mounting said interior rearviewmirror assembly to the mirror mounting button attached at the interiorsurface of the windshield of the vehicle.
 14. The interior rearviewmirror system of claim 7, wherein said application specific integratedcompass chip is oriented in a manner that reduces the effect of anadjustment of said mirror casing on the output of said magnetoresponsivesensing elements.
 15. The interior rearview mirror system of claim 1,wherein said application specific integrated compass chip is operable toreceive an output from a temperature sensor and to determine atemperature reading and to display the temperature reading on saidinformation display.
 16. The interior rearview mirror system of claim 1,wherein said application specific integrated compass chip furthercomprises a temperature sensor and wherein said temperature sensor iscommonly established with said magnetoresponsive sensing elements andsaid associated circuitry on said semiconductor substrate.
 17. Theinterior rearview mirror system of claim 1, wherein said reflectiveelement comprises a variable reflectance electro-optic reflectiveelement and wherein said application specific integrated compass chipcontrols, at least in part, the reflectance of said electro-opticreflective element.
 18. The interior rearview mirror system of claim 1,wherein said at least two magnetoresponsive sensing elements comprisefirst, second and third magnetoresponsive sensing elements.
 19. Theinterior rearview mirror system of claim 1, wherein said at least twomagnetoresponsive sensing elements comprise at least two Hall effectmagnetoresponsive sensing elements.
 20. The interior rearview mirrorsystem of claim 1, wherein said interior rearview mirror system entersan initial rapid compensating mode in response to an ignition cycle ofthe vehicle to achieve at least an approximate compensation for adeviating magnetic field of the vehicle, and wherein said interiorrearview mirror system automatically exits said rapid compensating modeand enters a less aggressive calibration mode that distinguishes theEarth's magnetic field from magnetic anomalies and non-abrupt changes inthe vehicle magnetic signature, and wherein said interior rearviewmirror system automatically exits said rapid compensating mode after apredetermined period of time has elapsed since the ignition cycle. 21.The interior rearview mirror system of claim 1, wherein said interiorrearview mirror system operates in an automatic compensation mode toachieve at least an approximate compensation for a deviating magneticfield of the vehicle and wherein the automatic compensation does notrequire the vehicle to turn through a 360 degree circle to compensatefor a deviating magnetic field of the vehicle.
 22. The interior rearviewmirror system of claim 1, wherein said information display comprises atleast one of (a) a vacuum fluorescent display, (b) a light emittingdiode display, (c) an electroluminescent display, (d) a liquid crystaldisplay, (e) a backlit thin film transistor liquid crystal display and(f) a video screen display.
 23. An interior rearview mirror system for avehicle, said interior rearview mirror system comprising: an interiorrearview mirror assembly comprising a mirror casing and a reflectiveelement; wherein said reflective element provides a field of viewrearward of the vehicle to a driver of the vehicle when said interiorrearview mirror assembly is normally mounted in the vehicle and isadjusted to a viewing orientation; wherein a mounting structure mountssaid interior rearview mirror assembly to an interior portion of thevehicle, and wherein said mirror casing is adjustable by the driver ofthe vehicle relative to the interior portion of the vehicle via at leastone pivot element of said mounting structure to adjust the rearwardfield of view of said reflective element when said interior rearviewmirror assembly is normally mounted in the vehicle; wherein saidinterior rearview mirror assembly comprises an application specificintegrated compass chip; said application specific integrated compasschip comprising at least two magnetoresponsive sensing elementsestablished on a semiconductor substrate, wherein said semiconductorsubstrate comprises a silicon substrate; said application specificintegrated compass chip further comprising associated circuitry commonlyestablished with said magnetoresponsive sensing elements on saidsemiconductor substrate; wherein said magnetoresponsive sensing elementsand said associated circuitry are commonly established on saidsemiconductor substrate using CMOS technology; wherein processing of analgorithm by a microprocessor of said interior rearview mirror systemdetermines a directional heading of the vehicle responsive to a sensingof a magnetic field by said magnetoresponsive sensing elements andautomatically compensates for a deviating magnetic field; and wherein aninformation display of said interior rearview mirror assembly displaysthe directional heading of the vehicle.
 24. The interior rearview mirrorsystem of claim 23, wherein said application specific integrated compasschip is disposed in said mirror casing and moves in tandem with saidmirror casing and said reflective element when said mirror casing isadjusted by the driver of the vehicle relative to the interior portionof the vehicle.
 25. The interior rearview mirror system of claim 24,wherein electrical wiring providing electrical power for saidapplication specific integrated compass chip passes through said atleast one pivot element of said mounting structure.
 26. The interiorrearview mirror system of claim 25, wherein said at least one pivotelement comprises two pivot elements that are part of a double pivotmounting structure, and wherein said electrical wiring passes throughboth of said pivot elements of said double pivot mounting structure. 27.The interior rearview mirror system of claim 24, wherein saidapplication specific integrated compass chip has an area of less thanapproximately two square centimeters.
 28. The interior rearview mirrorsystem of claim 27, wherein said application specific integrated compasschip further comprises a temperature sensor and wherein said temperaturesensor is commonly established with said magnetoresponsive sensingelements and said associated circuitry on said semiconductor substrate,and wherein said application specific integrated compass chip isoperable to determine a temperature reading for displaying thetemperature reading on said information display.
 29. The interiorrearview mirror system of claim 23, wherein said reflective elementcomprises a variable reflectance electro-optic reflective element andwherein said application specific integrated compass chip controls, atleast in part, the reflectance of said electro-optic reflective element.30. The interior rearview mirror system of claim 23, wherein said atleast two magnetoresponsive sensing elements comprise first, second andthird magnetoresponsive sensing elements.
 31. The interior rearviewmirror system of claim 23, wherein said at least two magnetoresponsivesensing elements comprise at least two Hall effect magnetoresponsivesensing elements.
 32. The interior rearview mirror system of claim 23,wherein said information display comprises a video screen display. 33.An interior rearview mirror system for a vehicle, said interior rearviewmirror system comprising: an interior rearview mirror assemblycomprising a mirror casing and a reflective element; wherein saidreflective element provides a field of view rearward of the vehicle to adriver of the vehicle when said interior rearview mirror assembly isnormally mounted in the vehicle and is adjusted to a viewingorientation; wherein a mounting structure mounts said interior rearviewmirror assembly to an interior portion of the vehicle, and wherein saidmirror casing is adjustable by the driver of the vehicle relative to theinterior portion of the vehicle via at least one pivot element of saidmounting structure to adjust the rearward field of view of saidreflective element when said interior rearview mirror assembly isnormally mounted in the vehicle; wherein said interior rearview mirrorassembly comprises an application specific integrated compass chip;wherein said application specific integrated compass chip is disposed insaid mirror casing and moves in tandem with said mirror casing and saidreflective element when said mirror casing is adjusted by the driver ofthe vehicle relative to the interior portion of the vehicle; saidapplication specific integrated compass chip comprising at least twomagnetoresponsive sensing elements established on a semiconductorsubstrate, wherein said semiconductor substrate comprises a siliconsubstrate; said application specific integrated compass chip furthercomprising associated circuitry commonly established with saidmagnetoresponsive sensing elements on said semiconductor substrate, andwherein said associated circuitry comprises a microprocessor; whereinsaid magnetoresponsive sensing elements and said associated circuitryare commonly established on said semiconductor substrate using CMOStechnology; wherein said application specific integrated compass chiphas an area of less than approximately two square centimeters; whereinsaid reflective element comprises a variable reflectance electro-opticreflective element and wherein said application specific integratedcompass chip controls, at least in part, the reflectance of saidelectro-optic reflective element; wherein processing of an algorithm bysaid microprocessor determines a directional heading of the vehicleresponsive to a sensing of a magnetic field by said magnetoresponsivesensing elements and automatically compensates for a deviating magneticfield; and wherein an information display of said interior rearviewmirror assembly displays the directional heading of the vehicle.
 34. Theinterior rearview mirror system of claim 33, wherein said applicationspecific integrated compass chip is supported by said reflectiveelement, and wherein said application specific integrated compass chiphas an area of less than approximately one square centimeter.
 35. Theinterior rearview mirror system of claim 34, wherein said associatedcircuitry comprises at least two of (i) an A/D converter, (ii) a D/Aconverter, (iii) signal processing circuitry, (iv) memory, (v) signalfiltering circuitry, (vi) a display driver and (vii) a vehicle businterface.
 36. The interior rearview mirror system of claim 35, whereinsaid application specific integrated compass chip further comprises atemperature sensor and wherein said temperature sensor is commonlyestablished with said magnetoresponsive sensing elements and saidassociated circuitry on said semiconductor substrate.
 37. The interiorrearview mirror system of claim 35, wherein said variable reflectanceelectro-optic reflective element comprises a variable reflectanceelectrochromic reflective element, and wherein said variable reflectanceelectrochromic reflective element has a transflective mirror reflectordisposed at a surface thereof, and wherein said information display isdisposed behind said variable reflectance electrochromic reflectiveelement and, when said interior rearview mirror assembly is normallymounted in the vehicle, said information display operates to display thedirectional heading of the vehicle for viewing by the driver of thevehicle through said transflective mirror reflector of saidelectrochromic reflective element.